Ian Darwin, EVangelist: EVs - Electric Vehicles, including cars, buses, ships, and planes - are the clean future of transport.

Ian Darwin, EVangelist: EVs - Electric Vehicles, including cars, buses, ships, and planes - are the clean future of transport.

How hard can it be to build a grid-scale solar farm?

How hard can it be to build a grid-scale solar farm?

So where does the electricity for EVs come from? One source is solar energy. Well, in fact, that’s the only source - all energy on this planet is originated by the sun’s nuclear reaction (other than nuclear reactors we build here, but we need the sun’s energy to build those too, and look at Chernobyl and Fukushima for how that can end). Most fossil fuel - oil, coal, most "natural gas" - is hundred-million-year-old photosynthesis products that we dig up and burn. Wind energy is produced by the sun warming different parts of the earth’s surface, causing air to move (and by the rotation of our planet, but that is held in our orbit by the sun’s gravity, so thanks again, Sun). But the most direct conversion method we have is photovoltaic (PV) or solar cell energy.

We hear quite a bit about "rooftop solar", which are solar cells on a building’s roof. This can be a useful source of energy under some circumstances. If it’s desired just to feed this energy into the grid, then almost any size of roof can be used. If it’s intended to provide off-grid power, or to fully power the building, then there are minimum sizes. A typical solar panel provides 250 watts of power and is about 2x3 feet in size. So it takes four of these to provide one kilowatt of energy - enough to run a toaster. So a tiny home is not going to be self-sufficient with rooftop solar if it has many appliances (these might want a ground-mounted rack with 12-20 panels and maybe a sun-tracker). For larger homes, typical of those in North America, rooftop PV can provide enough for much or all of the house’s energy needs for part of the day and, with local battery backup added, possibly all day and night (except when it snows 🤨). Panels continue to drop in price, but local battery backup remains expensive for home use. As well, the cost of the "inverter" (converts direct current from the solar panels into alternating current for use by lights and appliances) and other infrastructure makes small installations less cost effective. So let’s cash in on the economies of scale: go big!

How hard can it be, indeed, to set up a commercial-scale solar energy farm? Don’t you just drop down some solar panels and hook them up to the electrical transmission network and rake in the money? If you’ve ever had the dream to do so, read on. But beware: it’s a non-trivial undertaking, typically taking years to plan and build.

Most large solar farms are in the business of supplying electricity to "the grid", the interconnected network of electrical distribution and supply for a given area. While there will usually, for example, be more than one cellular phone service provider in a given area, because of the cost or runnning high voltage distribution wires, there will usually be only one "grid" covering a given area. Assuming that that’s the market you want to be in, here is a simplified look at a few of the major steps, only very roughly in order:

  • Find some land that isn’t in use (or land whose use can co-operate with solar);

  • Make sure you will be able to get permission to use this land for a long term (buy, lease, etc.);

  • Look up how many KWh/m2 of solar energy your site gets on a yearly basis;

  • Multiply that by the efficiency rating (today’s best cells give about 25% efficiency when new);

  • Decide if you will only sell by day or if you will also provide energy storage to level out daily peaks (since solar cells don’t work at night);

  • Storage may include battery (e.g., Tesla MegaPack), pumped hydro, heat pumps, etc.; these are based on existing technology and, other than pumped hydro, work anywhere.

  • Meet with the electrical authority and get (don’t sign yet) a contract for selling them electricity;

  • Consider environmental issues which can block sunlight: snow? salt air? airborne dust/dirt? bird droppings?

  • Determine if the site will in fact pay for itself;

  • Arrange building permits, environmental assessments, and other bureaucracy needs;

  • Arrange financing, which may include loans, issuing shares or bonds, tax breaks, subsidies, or other sources - as would any large energy project;

  • Find reputable contractors (one or more, to do site prep, providing and installing the solar panels, doing the grid hookup, etc.) and get competing quotes.

  • Unlike the fossil fuel industry[1] renewable energy providers should include cost set-aside for end-of-life handling, since today’s solar cells have an expected 80% lifetime of about three decades. They should be usable well beyond that, but below 80% of capacity they will not likely be profitable. Solar panels are of course much easier to decommission than oil wells and, if recycling facilities aren’t available yet, can be warehoused for far less than the cost of oil well cleanup.

Whew! Are we there yet? No, not really. There is a wealth of detail to consider. Here are some book-length presentations on this subject. The first two are free downloads (the second is an updating of the first), both from IFC, in cooperation with the World Bank. The third is a traditional publication. Speaking of detail, the IFC book has two full pages just full of abbreviations to learn!

Apologies for any errors and omissions in this posting; my cat insisted on helping me type it.


1. See for example Uk taxpayers on hook for ï¿¡24,000,000,000 cleanup costs, almost a tenth of what the entire dying North Sea oil industry produced in revenue to the taxpayers over its lifespan, and Canadian taxpayers could be dinged up to C$70,000,000,000 in oil well cleanups.

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