Why are U.S. homeowners seeing delays in solar installations? Australia recently topped its rooftop solar panel installation record reminding nations worldwide that residential solar can play a significant role in creating energy independence while reducing carbon emissions. It’s not price that is holding solar back because in the U.S. the cost of residential solar has never been more competitive because of the IRA and state policy initiatives. Solar is getting lots of positive press, so why aren’t homeowners taking to it faster? 

Disrupting Solar’s Shining Reputation

The problem lies with solar providers. Homeowners are becoming jaded by slowly deteriorating reputations. Even with the tax credits and promotions, arrays to power homes remain expensive requiring tens of thousands of dollars in investment and resultant financing.

Installers who don’t know what they are doing may not hook up the rooftop solar installation to the grid so homeowners end up receiving a standard utility bill while having to pay back the cost of the installation which defeats one of the purposes of going solar in the first place. Why should a customer sign a contract to pay for panels that may not work the way they are supposed to for months? Why is this even happening?

Because of poor business practices from solar companies, the consumer allure of renewable energy and the contribution it can make to a green future is eroding.

Analyzing the Supply Chain

The solar industry is facing supply chain problems. This is not a unique experience with the past few years seeing major disruptions to world trade. Obtaining the raw materials and the manufacturing capacity to meet rising demand appears to be happening for almost every product in the global market. So despite the demand being driven by climate concerns and skyrocketing utility prices, the solar industry is falling short. Would more solar panel providers entering the market overcome supply and demand challenges? Not necessarily if material capacity remains constrained.

The real issue is simple. Most of the world’s solar panel materials come from China, and that’s where the distribution bottlenecking is happening. This sole source reliance makes meeting demand next to impossible. No solar provider has a chance to keep sufficient stock because too many are reaching into the same small pot. So adding more solar installation companies doesn’t solve anything. 

Another challenge is personnel. There are shortages of workers to transport, harvest and engineer solar panels much less install and connect them to the grid. And there also is an insufficient effort by solar panel contractors to teach customers panel maintenance which would reduce service calls. 

Accelerating Progress Without Interconnection

Solar energy technology continues to advance faster than most humans can handle. As a result, solar installer practices to keep the technologies operational aren’t always state-of-the-art. The software and online systems for submitting documentation to allow customers to plug homes into the grid remain buggy.  

Applications and documents are lost. Clients get forgotten. Flawed systems flag common mistakes or human errors as rejections, leaving customers empty-handed. Customers have argued that the sector’s inefficiency is pushing prospective customers to get proof beforehand that a solar contractor has stock availability before signing on the dotted line.

Delays in rooftop solar adoption in the U.S. are also being caused by providers and regulatory bodies failing to consider the broader lens of technological assets necessary to support demand and regulate automation to balance workloads. Tending to IT issues constantly means resources are unavailable to help hook homes to the grid or advocate for infrastructure changes that would support solar growth.

The communication problems aren’t solely internal because solar panel providers and contractors are asked to work with city planners and engineers. Not all city power grids can handle current residential solar panels let alone an influx of the latest solar technologies. And then there are the utility companies that restrict grid access because they don’t want to lose revenue when rooftop solar reduces electricity demand. 

How Solar Delays Are Impacting Progress to Net Zero

The U.S. solar industry needs a good kick in the can to sort out its many problems and challenges. The U.S. is among the world’s nations, an energy hog. Much of that energy continues to be produced by greenhouse gas-emitting power stations. The world can’t afford the U.S. as a laggard in increasing the amount of consumer-based solar power.

A sustainable future requires a better solar plan. No one should have to wait 1,131 days to see their rooftop solar system approved and connected to the grid as was demonstrably documented by Bill Maher, the HBO comedian on his Real Time talk show.

Solar energy from space has been the dream of science fiction writers beginning with Isaac Asimov back in 1941 in a short story called Reason which later was included in a collection that Asimov published in 1950 entitled I, Robot. In the story, Asimov described a space station that collected energy from the Sun and transmitted it by microwave beam to various locations. Asimov recognized the distinct advantage of building solar power generating stations in space out of the Earth’s shadow and therefore continuously being able to harvest the energy of the Sun.

When the first telecommunication satellites were launched into geosynchronous orbits around Earth, it became obvious that not just communications could be offered in a continuous stream using satellite technology. A photovoltaic array parked in a similar orbit would stream electrical energy to Earth ground receivers. And depending on the size of an array deployed at that altitude, a satellite or a few of them to ensure no single failure, could become an endless supplier of all the energy the planet would need. There were technical problems still to work out.

For example, how could a large array be deployed in space? Currently, the International Space Station’s (ISS) latest upgrade of its solar panels demonstrates such a technology. Called the Roll-Out Solar Array (ROSA) its deployment makes it possible to send large arrays to space in small form factors that can physically roll out to extended lengths. Although deployed on the ISS, the potential for this technology to be used in building large solar-power stations in space is considerable.

The second big challenge is how to get the energy collected down to Earth receiving stations. The SSPD prototype includes three component systems that address these two challenges.

1. The Deployable on-Orbit ultraLight Composite Experiment (DOLCE) is a new solar array architecture composed of ultrathin modules that can be expanded to create a kilometre-scale array.
2. A collection of 32 different types of photovoltaic cells which has been given the name ALBA will assess which of these can work best in the harsh environment of space.
3. The Microwave Array for Power-transfer Low-orbit Experiment (MAPLE) is an array of lightweight microwave power antennas designed to focus on two receivers down on Earth to demonstrate the capacity to transmit power to multiple targets on demand.

An onboard computer system interfaces with all of the components.

How Directional Wireless Power Transmission Works

The SSPD array of multiple antennae is designed to transmit power phased simultaneously and timed precisely as a highly directed energy beam focused on Earth-based receivers. In SSPD the conversion is to microwaves which are received on the ground and then converted back to electricity.

Caltech isn’t alone in exploring solar power transmission to Earth. Northrop-Grumman is working with a technology it calls SSPIDR in partnership with the U.S. Air Force Research Laboratory (AFRL). The European Space Agency (ESA) has its Advanced Concepts Team (ACT) working on a similar project. And China, last June, announced its plans by 2028 to put a demonstration satellite in low-Earth orbit (400 kilometres in altitude) to test converting 10 Kilowatts of generated solar energy to microwaves or lasers and transmitting a directed beam to multiple targets on the surface.

When will we know the Caltech technology works? Sergio Pellegrino, a Professor of Aerospace and Professor of Civil Engineering at Caltech, in a January 2, 2023 press release states “We should know right away if DOLCE works.” Which photovoltaics prove to be the best will take about six months of tests.

MAPLE is another story. Ali Hajimiri, a Caltech Professor of Electrical and Medical Engineering, is also quoted in the press release talking about the building of this component in the prototype. He states, “The entire flexible MAPLE array, as well as its core wireless power transfer electronic chips and transmitting elements, have been designed from scratch. This wasn’t made from items you can buy because they didn’t even exist.” It will take several months to verify MAPLE is performing to specification.

Could all of Earth’s electricity needs be supplied from space-based solar power stations? The American Society of Mechanical Engineers (ASME) says space-based solar panels can generate 2,000 Gigawatts of power constantly, or 40 times more energy than solar panels on the Earth. The technical challenges include the ability to overcome launch costs to get materials into space (SpaceX is demonstrating reusability which is dramatically reducing payload costs), lightweight easily deployed solar panels (ROSA sounds like a fit), microwave-or laser transmission equipment and receiving centres on Earth to collect and distribute the energy (which Caltech in this prototype should be able to demonstrate.)

So by the summer of this year, Caltech’s design team should know if they have a working prototype for solar power stations in space. The implications for the planet and its energy future are enormous. We could see a significant space-based energy industry in place by the mid-2030s. The fossil fuel industry and utility companies may want to pay close attention to what Caltech is doing.

What Jane is describing is complementary to Wind Catcher and if I were an energy utility company looking for green solutions, I’d be paying considerable attention to solar farms on water and Wind Catchers.

Solar farms provide utilities with unique solutions to solve their goals of lowering the carbon footprint of the energy they deliver. But solar power is challenged by the need to be in sunlight. Not all locations provide enough hours of direct sunlight every day. Many rooftops aren’t designed to take solar panels. But one of the biggest challenges is that large arrays of solar panels, called solar farms, can take up a lot of space tying up hectares of land that can be used for alternative purposes such as growing crops. As a result, an emerging alternative implementation of the technology is focused on building solar farms over water rather than land. 

What Is a Solar Farm?

A solar farm, also known as a photovoltaic power station, is a large collection of solar panels placed in one area connected to the grid. The first solar farm was launched in 1982 in Hesperia, California. Since then, utilities and companies have built many more. The usual locations are where there are few people, ample sunlight, minimal wetland habitat and flat surfaces. This helps to maximize their efficiency. 

Why Place Solar Farms on the Water?

Farmers and conservationists don’t always approve of land-based solar farms because the installations cover areas that can be used for growing crops, grazing livestock, or preserving wildlife. A solar farm can impede a wildlife corridor and range where migratory animals and grazing animals travel regularly. A solar farm could cover an area that is home to sensitive and endangered plant species that require full sun. The shadow cast by the panels could disrupt their growth.

In some countries, India for example, there simply isn’t space for land-based solar farms. With its rapidly growing population, India needs to conserve all the land it can for food production. That’s why floating solar farms are seen as appealing. The waterways, reservoirs and oceans upon which they ride will never be used for farming and raising livestock. Although, in the future, we may see floating cities built which would make floating solar farms a valuable energy-producing adjunct to these novel human settlements. 

From companies maintaining overwater infrastructure, particularly in ocean environments, there are unique challenges caused by saltwater interacting with sensitive equipment. Currently, a growing technological capacity to maintain equipment in these environments should be transferable to floating solar farms soon.

Ecosystem Impacts from Floating Solar Farms

Where to Find Floating Solar Farms Today

Aquatic solar farms are becoming more common worldwide. Here are a few countries using this technology:

India

On the Omkareshwar Dam, the state of Madhya Pradesh is constructing a giant floating solar plant. The plan is to have it operational by 2023. The panels will be able to automatically adjust their position based on fluctuating water levels. 

United States

In California, the Healdsburg Floating Solar Farm is situated at a wastewater treatment plant. It’s the largest floating solar farm in the United States. The two-sided panels capture energy from the sun above, and also from below as it reflects off the water. 

Thailand

The energy plant on the Sirindhorn Dam has the claim to fame as the world’s largest floating solar farm. Comprised of over 144,000 individual panels, the massive plant generates energy from both solar and hydropower. Since it became active a year ago, it has already generated 60 million kilowatt hours of electricity.

Germany

Floating on a lake that formed in an unused quarry near the town of Haltern am Sea, this floating solar farm is the largest in the country providing 3 Megawatts of power. It is one of many renewable energy projects that Germany hopes will help it to wean itself off fossil fuels coming from Russia in the wake of the war in Ukraine. 

Portugal

Europe’s largest floating solar farm can be found on the Alqueva Reservoir. Its 12,000 panels are supplying enough energy for up to a third of the residents in nearby towns. 

Where to Find Floating Solar Farms Tomorrow

This week a Dutch-Norwegian joint venture is planning to deploy a floating solar farm combined with an offshore wind farm off The Netherlands. The company, SolarDuck, will be the first to build a hybrid demonstrator project at this scale. It is one of several planned and under-construction pilot over-water solar farm projects currently on the go and will be located 53 kilometres (33 miles) offshore.

The growing interest globally for floating solar farms is being driven by climate change and a solution that doesn’t take up valuable land suitable for growing food. Combined with other over-the-water renewable energy solutions like wind farms as planned by SolarDuck and others, the technology should see significant growth through the rest of this decade and beyond. Market perceptions are very positive. Valued at US $2.55 billion in 2021, the floating solar farms’ industry is expected to grow to more than $10 billion by 2030. Why? Utilities see advantages in deployment because they are scalable, easy to assemble, adaptable, and can be integrated with other renewable technologies like wind on and over the water.

Solar panels allow you to be eco-friendly and save on utility bills. The recent Inflation Reduction Act’s passing in the United States is expected to cause a spike in solar panel sales that currently are already receiving rebates and credits from suppliers. But some places on the planet may be more prone to natural disasters, especially coastal and high-wind areas. That’s why solar system owners need to know before installation how well the panels they are buying can withstand natural disasters. Are some more durable than others?

Floods and Storms

Climate change is leading to increasing severe weather events. Rain can cause floods. And above the ground thunderstorms, lightning and hurricanes can wreak havoc on infrastructure. Solar panel technology, however, is proving to be more resilient than in the past because of technologies like micro-inverters placed under rooftop solar panels to optimize their power. This allows homes affected by a natural disaster to operate without battery backup during the day. 

Solar panels are waterproof, meaning they can continue to generate electricity even when soaked, feeding generators to prevent blackouts. Their ability to create power from indirect sunlight allows them to work even in cloudy conditions. And rainfall can help remove debris like pollen and dirt on panels to improve their energy conversion efficiency. 

However, there are a few considerations related to solar in the face of floods. First, most solar panel wiring systems, like inverters and breaker boxes, are placed close to ground level which means it is important to protect these fixtures from inundation and add flood assistance and prevention technologies.

In non-roof installations, solar panels on the ground can be uprooted if not properly anchored. If you live on flood plain consider the following:

• change the location of your solar installation to move it to higher ground.
• Design a stormwater runoff system or put in retention ponds to capture and remove floodwater
• Build your solar panel installation with higher clearance.

Despite the metal used in solar panels, they don’t increase the risk of any home being prone to a lightning strike. Lightning isn’t actually attracted to metal, and solar panels are usually constructed from glass and aluminum (the latter is s non-magnetic metal).

Blizzards and Hail

Monocrystalline and polycrystalline panels are certified to withstand up to one inch of hail falling at speeds of up to 80 kilometres (50 miles) per hour. In 2017, when Denver suffered from a hailstorm that dropped stones the size of golf balls, it provided an opportunity to analyze the strength of over 3,100 solar panels in the area. Only one installation was affected despite cars and buildings receiving extensive damage. So for the most part solar panels are built strong enough to take a beating. 

Snow and ice are of greater concern because when they blanket panels they are unable to generate electricity. Fortunately, Brushing and scraping are the answer to get the panels working again. An interesting fact is that solar panels can perform just as well, if not even better, in snowier environments. And recent advancements have improved the ability of panels to shed ice and snow with coatings of oils, PVC and PDMS plastic.

The biggest safety concern in extreme snow conditions would be the weight-bearing ability of the panels. That’s why manufacturers test the load-bearing strength of their solar panels.

Tornadoes and High Winds

Wind gusts can sneak into the space between your roof and the installed solar panels creating an uplift. With proper installation this is preventable. The likelihood of panel loss would be in extreme wind conditions such as a Category 5 hurricane where gusts would exceed 225 kilometres (140 miles) per hour. Under such conditions, your roof is more likely to blow off along with the solar panels. Most tornadoes never exceed these windspeeds although the highest recorded within a funnel cloud exceeded 480 kilometres (300 miles) per hour.  

Solar companies and installers recognize the need to make their panels even more robust in regions prone to natural disasters. Heterojunction solar cell technology (HJT) combines monocrystalline with a thin film to withstand high winds and work well in low-light conditions. These types of panels became more popular after significant storms like Hurricane Maria. The State of Florida requires solar companies to guarantee that their installations can withstand above-average wind gusts up to 274 kilometres (170 miles) per hour.

Another concern about high wind events is that they can cause sandstorms and haboobs. But as long as the wind speeds don’t exceed the upper limits, the only consequence for solar panels is the debris that will land on their surfaces reducing their conversion efficiency.

Earthquakes and Wildfires

California is prone to earthquakes. California homes, therefore, are susceptible to the kind of damage earth-shaking events can do. That means their rooftop solar arrays are equally susceptible. Obviously, extra precaution by solar installers is needed there and the state doesn’t allow for solar installations to be constructed directly over areas on seismic faults. Japan, which is also in an earthquake zone is promoting innovative monocrystalline foldable panels with disaster prevention in mind. 

Wildfires produce ash which acts very much like the blown sand we described earlier that can accompany windstorms in dry areas. Ash decreases solar irradiance as does the smoke from wildfires reducing solar panel efficiency. Panels can also catch fire. Panels are fire-rated based on superstrate material and frame type. So if you live in an area where wildfires happen and want to install rooftop solar, talk to your contractor about which panels would be best.

Solars Panels in Natural Disasters

With climate change and the pursuit of renewable energy, improving solar panel efficiency is a high global priority. When Hurricane Sandy struck Long Island, the Jersey Shore and New York City, entire neighbourhoods lost power for days. Among the first emergency energy technology deployed was portable solar panels (see the above picture). Solar panels are for many remote places a viable energy source replacing diesel generators that require the transportation of increasingly expensive fossil fuels and that put carbon into the atmosphere.

And in the very near future, we may even see wearable perovskite solar panels that can be applied to clothing, tent walls, curtains and almost any other surface as a first-response energy solution.

As I previously stated, a solar panel here on Earth that converts 20 to 30% of sunlight into electricity represents the state-of-the-art. That panel in space would be thirteen times more efficient.

In looking at how we can harvest solar energy in space and deliver it to Earth-based receiving stations for transmission through local or national grids, several alternatives to kilometres-square arrays have been proposed.

One borrows from the current strategy SpaceX is using to deploy a telecommunications network using a constellation of orbiting satellites to provide global coverage for data, images and voice transmissions. The Starlink network uses low-Earth orbiting satellites that provide high-bandwidth, high-speed telecommunications for those who install a receiver and subscribe to the service. Currently, there are more than 2,300 Starlink satellites with plans to grow the constellation to between 12 and 30,000 more. They orbit at altitudes between 345 and 570 kilometres (215 to 340 miles). They are interconnected so that a call or transmission gets handed off with little disruption in what is referred to in industry vernacular as low latency. This interconnectedness is a characteristic of mesh networks.

And what can work for telecommunications could conceivably also work for the transmission of solar energy to our planet’s surface. The size of the constellation of satellites would have to be on a similar scale to Starlink to ensure that despite as many as half of the constellation being in Earth’s shadow at all times, there would always be a sufficient amount of energy being collected and fed to receiving stations on the surface. The method of energy transmission to the planet would be microwave but the satellite constellation would be interconnected using lasers.

A prototype or pilot test of this concept is far easier and cheaper to do than the proposed UK demonstrator described in Part One in this series. Build a few or one and a few receiving stations on Earth to test and see if the satellites can direct their microwave energy to do the job. Then like the Starlink network, start building the constellation using economies of scale and like SpaceX, launch them 50 or more at a time until you reach a critical mass for global coverage.

What is interesting is just how close we are to developing this solar power from a space model concept to reality. In 2020, the US Department of Defense demonstrated a technology that is applicable on one of its X-37B uncrewed shuttle missions. As the mini-shuttle circled the Earth, a pizza-box-sized solar panel was collecting energy from the Sun for transmission. A test system called PRAM, standing for Photovoltaic Direct Current to Radio Frequency Antenna Module, captured the energy from the panel which was sufficient to power a tablet computer here on Earth. A 2021 published paper in the IEEE Journal of Microwaves, entitled Microwave and Millimeter Wave Power Beaming, provided details about the technology and test done during the X-37B mission.

If we were to consider another use for this type of technology, think about being able to provide power to a specific location on Earth in the event of an emergency. The receiving technology could be portable for such a purpose and shipped anywhere it is needed. As a point-to-point system, its immediate application would be to provide electricity in the face of a natural disaster or war where standard power infrastructure was disrupted.

Could it be weaponized by a rogue nation or bad actor a la James Bond? The system designed for the X-37B experiment only could begin to send a microwave beam to Earth when the ground station acknowledged the handshake and gave it a green light.

And going beyond its emergency use application, as a constellation of solar power generating satellites, it could be used to light up those areas of the planet that today are underserved and meet the insatiable energy appetite of humanity for this century and beyond.

Both concepts wish to take advantage of uninterruptible solar energy which has been an aspirational goal for a long time but no single country as of yet has developed a feasible project. The reasons to do it, however, are tantalizing: 100% renewable energy for as long as the Sun continues to shine without interruption.

Today a state-of-the-art solar panel on Earth can convert between 20 to 30% of the energy it collects from sunlight into electricity. At night solar panels here contribute nothing. But in space with nothing to block the Sun, that same Earth-based solar panel becomes thirteen times more efficient. And that is enough of an incentive to consider solar power from space.

The Chinese and UK models are massive arrays located in geosynchronous orbit while continuously beaming energy to receiving stations here on Earth.

The US model is different using a constellation of solar power generating satellites. These would be in relatively low orbits and interconnected to form a mesh network. The total network would generate continuous energy beaming it to the surface even when a portion of it gets blocked when the satellites enter the night side of the planet.

In this two-part posting, we look at the Chinese and UK models.

China and the UK Propose Monster Solar Arrays

What experience to date can we apply to build what both China and the UK are proposing – monster arrays that would span multiple square kilometres in geosynchronous orbit? There are quite a few telecommunications satellites today in geosynchronous orbit. None are the size of what is being proposed. But we know how to get there from Earth.

Building something big in space has only one current model. It currently orbits 400 kilometres (248 miles) above the Earth and is the International Space Station (ISS), a structure several football fields in size. The ISS was built from modules and components delivered to the low-Earth orbit site and then assembled. It took ten years and $150 billion US  and costs about $3 billion for annual maintenance, not including astronaut visits and provisioning for the onboard crews.

A solar power array of the size being contemplated could be built from modular components sent into space where assembly could occur in low-Earth orbit in a similar fashion to the ISS. China has some experience already in building its own space station, Tiangong, using a similar technique. But the solar power array as envisioned by China would be a structure 25 times larger than the ISS. The simple math would suggest for such a structure costs could be 25 times higher. That means to build it could run up a $3.7 trillion bill.

If the site of the build is a low-Earth orbit, the solar power array would after completion have to be moved to a geosynchronous orbit 35,786 kilometres (22,236 miles) above the Earth. A move of this type at this scale would be unprecedented. Likely the means of propulsion would be plasma or ion thrusters, or maybe a novel use of a series of solar sales which could be deployed to move the completed array to its permanent location. Then finally there needs to be a receiving station on Earth that can capture what the array sends back to Earth in the form of microwave beams. There is the experience we have in building large radio telescopes and networks of them, and we know how to build large solar farms. But the antenna array will need to collect energy from the array that when transmitted to Earth must be diffuse enough to not harm anything or any creature flying through it. At the same time, there should be little in the way of energy loss in transmission from space.

From a recent UK feasibility study that looked at building a solar power array in space similar to what China is envisioning, British engineers have concluded that a geosynchronous orbiting power station is viable and can be built from materials launched from Earth. The study calculated the need for 300 launches equivalent in capacity to SpaceX’s current Starship. That would be enough to deliver materials for the assembly of a demonstrator array several kilometres in size by 2035 and capable of generating Gigawatts of electricity. The UK proposed array would be built by robots in the geosynchronous orbit location. Once the demonstration proves it works the array would continue to grow in size encompassing a significant space footprint.

The British call their project CASSIOPeiA which stands for Constant Aperture Solid-State Integrated Orbital Phased Array. (I wouldn’t have considered this particular acronym because if my Greek mythology is right, Cassiopeia was a vain African queen who was punished for her hubris by Poseidon and tied to an upside-down chair where she hangs today as the constellation that goes by her name.)

There is a Downside to a Geosynchronous Solar Power Station

The first question that comes to mind is — is one of these things enough? Redundancy in infrastructure makes for better outcomes as telecommunications companies will tell you. They learned about redundancy in their networks by overbuilding relays and substations to meet a five 9s standard. That’s 99.999% uptime or no more than 2 minutes of downtime for dial tone annually.

Power companies on Earth aspire to get close to five 9s but the cost to build redundancy into generation and delivery comes at a much higher cost. Even then utilities can be hit by unanticipated extreme events that normally would seldom interrupt dial tone. We are talking about hurricanes, tornadoes, wildfires, earthquakes, and tsunamis.

For a geosynchronous orbiting power array, there are space equivalents to extreme events that happen here on Earth. I can name three.

1. Geomagnetic storms caused by solar eruptions eject massive amounts of material into space. Referred to as coronal mass ejections (CMEs), these consist of magnetically charged particles that seriously disrupt satellites and even ground-based infrastructure. They last from hours to days. A recent Starlink SpaceX launch suffered a loss of 40 of its satellites because of a CME. Starlink operates in orbits much closer to Earth and therefore is more protected from CMEs and other space weather. But a geosynchronous solar power array would be far more exposed and the damage to it could be significant.
2. Solar radiation storms are another form of solar eruption. These are solar flares that are less spectacular than CMEs but nonetheless pose considerable danger. A stream of particles from solar radiation storms can cause radio blackouts on Earth. It can damage satellites and humans on the ISS need to find shelter in special areas of the structure when one of these phenomena erupts.
3. Solar x-ray emissions stream from the Sun and negatively impact radio and telecommunication signals here on Earth. These emissions also can cause radio blackouts. They interfere with GPS and can alter the positioning and operation of satellites in low-Earth orbit. For an array parked in geosynchronous orbit, the negative impact of x-ray emissions would be the threat to communications from Earth for the purpose of doing operational maintenance.

If we are to build solar power arrays as conceived by China and the UK then we will need to ensure that these massive projects in orbit will not suddenly go dark on us. We will have to build self-repair capacity into the structures, and to a degree overbuild them beyond 100% performance capacity. The question we have to ask is not can we build it, but more can we afford it?

But the US may have a solution that would make the vulnerabilities we have identified for a geosynchronous solar solution go away. And that’s what we will describe in Part Two.

The researchers have called their invention, WEC²P, which is an acronym for the Water-Electricity-Crop-Co-Production system. It consists of an array of solar panels placed atop a downward-sloping box with a spout at the bottom. During the day as the panels generate electricity, the waste heat produced transfers to the underlayer of hydrogel which causes water within it to evaporate and condense on the underside. At night as temperatures drop, air circulates under the panel to produce further condensation with the water collected for storage.

In a June 2021 two-week test, a panel the size of a small desktop generated 1,519 watt-hours of electricity and produced 5.1 litres. The water collected was used to irrigate a planting chamber with 60 spinach seeds. The results of the experiment can be seen in the images appearing below.

A description of the technology was published this month in the open-access journal, Cell Reports Physical Science. The authors are Renyuan Li, Mengchun Wu, Sara Aleid, Chelin Zhang, Webin Wang, and Peng Wang, all affiliated with the Water Desalination and Reuse Center, in the Division of Biological and Environmental Science and Engineering at KAUST.

In the introduction to their paper they write:

“Stable supply of water, energy, and food are the three of the most essential and indispensable factors of modern life and are keys to universal achievements of the United Nation’s Sustainable Developments Goals by 2030.”

They continue noting an urgent need for “holistic approaches” to address the three human needs which impact the 2 billion globally who lack safe drinking water, the 800 million who have no access to electricity, and the up to 700 million who suffer from food insecurity and famine. They designed WEC²P to address all of these, but in particular, the immediate focus was on the 300 million living in North Africa, South Asia, the Middle East, and other arid and semi-arid climates.

Harvesting water from the air has been a pursuit of many. Back in 2019, I described work by researchers at the National University of Singapore, who were developing a hydrogel to capture water from the air, or ocean and release it as fresh. In another project in 2017, I wrote about collaborative work being done by teams at the Massachusetts Institute of Technology, UC Berkeley, the Lawrence Berkeley National Laboratory, and King Abdulaziz City for Science and Technology, in Riyadh, Saudi Arabia, who were developing a technology called MOF, an acronym for Metal-Organic Framework, a sponge-like honeycomb device that caused water vapour to condense within it even in very low-humidity environments.

But what sets this new invention apart from the others is its ability to address both energy self-sufficiency and freshwater production. The photovoltaic panels used by the KAUST team are off the shelf and produce average electrical conversion efficiencies of around 15%. But with the added hydrogel their efficiency improves by as much as 9% because the gel absorbs the heat and lowers the panels’ temperature. The condensation chamber beneath the panels includes a wick placed within a silicon tube which captures the water vapour and condensation rather than allowing any of it to evaporate.

To test the effectiveness of the device for crop production, the outfitted growing chamber beneath the solar panels was set up to provide cooling power should to installed fans if the air temperatures had exceeded 50 Celsius (122 Fahrenheit) which would have been detrimental to the test plants. But fortunately, throughout the June 16 to July 1, 2021 period of the test, daytime temperatures never exceeded that threshold.

It’s an idea born from science fiction writer, Isaac Asimov, who described space stations transmitting solar energy to Earth using microwave beams back in a 1941 short story. And since the 1970s various subborned attempts have been made to turn Asimov’s fantasy into a reality. That includes work done by Japan’s space agency JAXA and the US Naval Research Laboratory.

In 2014 the US Department of Energy described what microwave transmission of energy to Earth would look like. It would involve satellites in geostationary orbit (GEO), 35,000 kilometres above the Earth. The solar reflectors would span up to 3 kilometres and weigh more than 80,000 tons. Each would generate multiple Gigawatts of power or enough to sustain a large city.

The microwave wavelengths used would long antennas, which would allow power to be beamed at low intensity to receiving stations regardless of atmospheric conditions. The intensity of the microwave beams would be no stronger than the midday sun allowing birds and airplanes to flying through them. The receiving antennae to collect the microwave beams would cover a large area of land. It was estimated anywhere between 3 and 10 kilometres in diameter.

In 2014, the estimated cost of launching, assembling and operating one of these satellites was estimated to be tens of billions of dollars requiring scores of material supply missions from Earth. At the time, there was no consideration of using space-based materials in the building of these geostationary satellite power arrays.

Currently, a British company, International Electric, has its own plans to beam power to Internet-of-Things (IoT) devices equipped with high-gain antennae for receiving power from a phased array, called CASSIOPeiA.

Now China is entering the field with plans this year to complete the Bishan Space Solar Power Station near Chongqing in an attempt to wirelessly collect energy beamed from a high-altitude balloon with a suspended floating solar array beneath. This test, if successful, will lead to a fully working small-scale power station and satellite to be deployed by 2030, and the ultimate goal, to harvest Gigawatts of energy from space using microwave power transmission.

So it appears we are witnessing another space technology race that could prove to be a zero-emission solution to end our reliance on fossil fuels for the bulk of our energy needs. Maybe, the latest IPCC Climate Assessment will hasten the research and development for these projects. It would be the ultimate solar energy solution with no intermittency issues whatsoever. What a game breaker that would be.

According to Bill Gates and the Breakthrough Energy Sciences (BES) organization founded by the Microsoft billionaire, the U.S. could achieve 70% carbon-free electricity and emissions reductions of 42% by the end of the decade. The cost, $1.5 trillion, $400 billion less than the current COVID rescue plan.

Achieving a renewable energy balance for the U.S. power grid will require investments in clean generation capacity and an enhanced transmission network to support it. Called the Macro Grid, the network will combine high-voltage direct current transmission (HVDC) with conventional AC transmission. Why a combination?

HVDC is more efficient for long-distance transmission. Renewable power generators like wind and solar produce direct current. Using HVDC combined with AC allows for the different regions of the U.S. to complement each other. Some areas like the Western states produce more renewable wind and solar while many Eastern states rely on thermal generated power using coal and natural gas. These power plants are more suited to AC transmission.

BES’s research has focused on four options to connect the country’s renewable resources to customers. It requires significant investments in new wind and solar capacity. Through these investments, the U.S. would be able to reduce annual grid emissions by 850 million tons.

The major challenge that wind and solar present is their variability as energy sources. How do you build an assured energy flow if the wind stops or the sun doesn’t shine? That means “we need to find ways to make the grid more robust to…these kinds of challenges,” states Dhileep Sivam, Vice President of BES.

Improved energy transmission across the U.S. would involve better integration of renewables and an increase in the grid’s resiliency. That’s why finding better ways to transfer electricity across the country is key to making renewable energy increasingly dominant.

In their proposals, BES notes that the energy captured from strong winds and sunny skies in different parts of the country needs to be available to consumers in places where those conditions at the time of generation do not exist. A windy day in Texas should be able to power up homes in California when there is no wind in that state. And a sunny day in California should be able to power a mid-western home in Texas on a day when local winds die down. If such were the case, the problems Texas faced during the recent polar vortex causing coal and natural gas thermal power plants to fail along with breakdowns in local wind turbines, would not have mattered because power would have been delivered to homes and businesses from across the grid originating elsewhere.

The BES proposals, which include upgrades to local AC transmission lines to link up short distances, and HVDC lines to connect resources crossing multiple states would lead to complete decarbonization of the U.S. grid by 2035, meeting the current administration’s targeted goals.

There are jurisdictional challenges to what BES is proposing. In the U.S., every state has sovereignty over energy generation and transmission. Utility companies tend to stay within political boundaries unless they are multi-state energy providers. Therefore local regulatory processes need to be overcome for the BES plan to succeed.

According to BES, if all states that have adopted 2030 clean energy goals were to meet them, the cost of upgrades would be $360 billion. The emissions reduction, however, would amount to a mere 6%, a far cry from the national target or the one proposed by BES above.

What’s missing from the BES plan. There is no discussion about energy storage and how adding battery capacity could impact the grid. Nor is there any mention of green hydrogen.

BES has made their model open source to allow anyone in the field to comment and contribute to the plan. Plans are afoot to look at Europe and other geographies.