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A TRIFECTA‍ ‍

Three problems and three solutions

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Solar energy, even when adding batteries to smooth out delivery, is often the cheapest form of energy. So why is it not scaling fast enough to avert serious extreme weather risks?

Three barriers stand in the way.

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THE THREE PROBLEMS

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1. Rural resistance to traditional solar "farms." Rooftop solar is not enough. We need large rural solar to meet existing clean energy demand. As rural communities push back against converting farmland into solar arrays, it's getting harder to find places to build big solar farms. Permitting is becoming more and more difficult.

Building a conventional "solar farm" often begins with bulldozing the topsoil off the land and covering it with gravel to suppress the vegetation that might shade the panels. This permanent destruction of agricultural capacity troubles farmers, many of whom see feeding people in a time of looming food insecurity as a noble cause. It also corrodes the farming-community culture. Former farmers become investors living off land rent or managing the proceeds from selling out, and even if they're supplementing that passive income with also working in town, it can destroy the sense of collegiality and common purpose in the community.

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2. Solar intermittency. People want electricity to be available all the time. Solar intermittency makes grid stability harder. Many industrial processes run 24/7. Shutting them down when the sun does not shine would damage equipment or break commitments those businesses have made to their customers. And retail customers also want 24/7 electricity.

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3. Inadequate grid connection and transmission. Utilities and grid operators have little motivation to connect solar farms. There is now more solar and battery capacity waiting in line for a grid connection than the entire existing U.S. solar power-plant fleet [1]. Solar developers wait an average of around five years for a grid connection [2], and most projects give up before they are ever built. Completion rates run only about 14 percent for solar and 11 percent for storage [3]. Capital markets do not have that kind of patience. Given that we are headed toward damaging extreme weather, this level of delay suggests a huge opportunity to make a difference.

The transmission lines are the other half of the problem. It generally takes ten years or more to get right of way and other permits for a long-distance, multi-state transmission line, yet more of that long-distance capacity is needed to move power from where the sun shines or the wind blows to where the energy is used.

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THREE SOLUTIONS

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Innovera is working to reduce the impact of all three barriers. And, we have the tools, processes, and experience to accelerate practical, profitable adoption of these solutions.

1. Agrivoltaics puts solar panels, with gaps between them, over 30 to 50 percent of a crop or pasture, as a tool of farming. For shade-tolerant crops and for grazing and forage, the alternating sun and shade as the sun crosses the sky reduces yield of many crops by less than 10 percent, and because the shade lowers heat stress and conserves water, it sometimes raises yield [4]. Light-hungry row crops like corn and soybeans take a larger hit, which is why agrivoltaics works best for grazing, forage, and shade-tolerant crops. It is also welcomed by farm workers, who often can relocate as the sun moves to keep working in the shade. Similarly, cows and sheep also often do better grazing in the shade.

In the right situation, adding electricity revenue on top of a nearly unchanged crop revenue can be an effective way to keep farmers in business. This matters because most U.S. farms already lose money on farming alone — about half of farm households report negative net farm income [5] and survive on off-farm income. Aggregate farm income stays positive only because a small number of very large operations produce most of the output and profit.

Agrivoltaics can help keep farmers in farming. And as farm communities learn more about it, their main reason for resisting agrivoltaics falls away. Already about 70 percent of U.S. farmers say they are open to solar on their land — as long as they can keep farming [6].

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2. Thermal energy storage can help with intermittency. A main solution is batteries to keep sending power when the sun does not shine, but enough batteries can be expensive and depend on minerals often mined in unethical or environmentally damaging ways. However, when the end use for the electricity is making heat or cold, which is roughly half of all final energy use [7], storing that energy directly as heat or cold can replace a significant part of the need for battery capacity. Thermal storage is cheaper than electrical storage and relies on shorter, less treacherous supply chains. Heat can be stored in high-tech ways, but also in systems as simple as hot water, or, for higher temperatures, an insulated box of bricks, stones, or sand. Cold, for many uses, can be stored as ice, other phase change materials, or chilled water. There is room for enormous expansion of thermal storage, and consequently a more cost-effective way than batteries to reduce some of the intermittency problem.

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3. Direct connection from agrivoltaics to large energy users. Within our broader work to accelerate agrivoltaics, we have chosen to focus on direct connection from an agrivoltaics project to a major user of power such as a data center or a wastewater treatment plant. This might require liberalizing microgrid rules to allow a dedicated transmission wire to cross roads and rights of way, but that is sometimes a local problem, and some localities are already liberalizing those rules. Indigenous nations, for example, often have the sovereign authority to set these kinds of rules on their own lands. We are identifying jurisdictions where the regulations make direct connection workable and sites where no road or right-of-way crossing is needed at all.

Given that data centers are increasingly required to generate their own electricity [8] and that gas turbine noise is now a leading objection to data centers in "bring your own power" localities [9], local or state governments will usually view noise-free solar, with thermal storage, and transfer of waste heat to useful purposes as preferable to gas turbines and direct air venting, and will often find a way to allow them to happen. Bypassing the congested grid altogether and using agrivoltaics instead of turbines sidesteps the interconnection queue, shortens timelines, and improves the economics for everyone involved except the utilities.

Direct, non-utility transmission from farm to large buyer can unlock rapid deployment, moving agrivoltaics down the experience curve to lower cost, proving models that reassure farmers, lowering the bank charges, and pulling solar developers into aggressive pursuit of the agrivoltaics opportunity.

This post has been about three barriers and partial solutions that Innovera is working on accelerating. We will go into more detail on how to make these things work and our progress in future posts. If humanity could scale all three of these solutions it would release a massive wave of climate progress.‍‍