Electric cars are the future. Is producing electricity to charge them cleaner than gasoline?

A friend of mine was from New Brunswick, and told me about the workers building the nuclear power plant there back in the 1970’s or 1980’s. The area had chronic unemployment, and the construction was as much a government work project as a power plant. He said workers knew when the plant was finished, they were out of a job. So all sorts of things went wrong - workers’ tools were welded inside the pipes, for example, knowing that when the quality check Xrays discovered th problem, they would be called back to repair it. Like every government project, it was a boondoggle that went far over budget, but the sunk cost meant it was too late to pull the plug.

To my mind, this is one of the problems - every one of these plants seems to be an expensive giant project designed from scratch, rather than built from cookie-cutter plans for cost and simplicity.

That’s right. These large state sponsored projects tend to follow a pattern whereby only a few very large companies can supply the manpower and expertise to deliver the project. Huge hydoelectric dams were like that. The defense industry is like that. Until very recently the space industry was the same with the few companies getting all the business and their costs underwritten by the taxpayer - cost plus accounting resulting in huge development costs. So it was with the nuclear power industry in the UK and France with its obvious connection to state security.

The UK spent a fortune on developing its own nuclear power plant design, the Advanced Gas Cooled reactor (AGR) and later a fast breeder reactor that created nuclear fuel for other reactors. The promise was that a technology could be developed that not only produced copious amounts of electricity but also created its own fuel. This was enormously attractive to governments.

They worked, but they needed a lot of maintenance and the economics proved to be a disappointment. They were expensive custom built designs that could not be easily manufactured. The US went in a different direction with the Pressurised Water Reactor (PWR) which is now the most common design. These could be a manufactured and sold on to other countries to recoup the development costs. Small PWR reactors are efficient and have lower maintenance. But…governments wanted a few big reactors and not lots of small ones. No-one wants one in their back yard and they require a lot of water and surplus heat. All the UK reactors are based on the coast. Eventually the UK decided to change to a PWR design and, of course, they had to be really big. So now we have the Hinkley Point C reactor being built at huge expense. The government is prevaricating about other sites.

Contrast this with off-shore Wind farms, which just keeps getting cheaper and neatly built on all the offshore building expertise that the UK acquired during exploitation of the North Sea Oil and Gas (with a bit of help from the Texans!). Building huge Windfarms in the North Sea is easy. Moreover the system the government has in place is to auction off areas of the North Sea to companies that are interested in developing wind farms and guarantee the first few a ‘strike price’ to cover the development costs. This ‘contract for difference’ system was developed during the North Sea Oil and Gas development and it seems to work. Each new area released seems to have a low strike price as the economies of scale kick in and the technology matures.

Everything about Nuclear is a headache except that it does have that attractive feature of supplying reliable baseload. So UK policy seems to be Wind and Nukes and gradually to turn down the Natural Gas plants. Coal has all but gone. Hydro is limited by geography, not enough suitable mountains and valleys. Some coal plants have been converted to burning biomass (wood chips from the US!). And the Interconnects to other countries. Fat cables the carry a few GigaWatts of power from other countries grids. This is a growth area. Solar…a few percent at most, this is not a country rich in sunshine.

What is missing is the big long term, grid scale battery. This is the missing invention of the 20th Century and so electricity generation became based around a design using an over provisioning of large power stations connected by a high capacity grid to distribute the power to consumers. If there was a big battery, the design would be very different. The growth of intermittent renewables such as solar and wind have upped the pressure for a solution to the grid storage problem.

Consequently the renewables power generation business faces criticism from the traditional power generators anxious to preserve their business interests and the whole thing gets politicised. Moreover, the nuclear lobby are also claiming that they can develop smaller, nuclear power plants that are much cheaper than the multi-gigawatt PWR designs. The Natural Gas industry is also fighting it corner with the ‘Blue’ Hydrogen designs and that somehow bury the carbon dioxide somewhere underground.

UK policy seems to be to hedge its bets. It is backing a lot of horses at the same time, see which one wins. But it is sold on a Green energy strategy that has wide political support.

Most European countries are having an internal debate about this, they all have a legacy of energy generation infrastructure deal with that is often quite different. France with its dependency of Nuclear and no gas network. Germany and many states in central Europe with huge coal power stations and a dependency on Russian natural gas. The politics takes on an international dimension.

The story in the US is quite different, kind of similar to China. There are huge renewable resources in some parts of the country and huge demand in others. I would have expected the US to start developing a national grid to connect the Mid-West sun and wind states with the big coastal cities where there are many consumers. But there seems to be a lot of problems with that. So maybe it will develop off-shore floating wind farms, despite the lack of convenient shallow coastal water.

The debate in Texas must be interesting, the home of the Oil and Gas business but with lots of Wind power and grid that failed dramatically. The threats and opportunities are written very large.

A little late to the discussion. I through a few observations I have as I’ve been driving a Chevy Volt for 8 years and have solar panels on my house as well.

The discontinued Volt operates as a pure electric until the battery dissipates, usually around 54 miles of range or so, then switches to a gas backup. On average I drive about 40 miles a day. Even given the few long trips, I buy a tank and a half of gas every year. It cost me about 85 cents of electricity to travel 40 miles. Compare that to local gas prices of $3.60 a gallon. That’s quite a savings.

I bought solar for my house a few years back. On average I save $150 a month on electricity costs versus not having them, including the monthly load payoff on the panels. It cost more for me not to have panels than have them. The panels cover about 40% of my power needs throughout the year, I need a lot of A/C so it definitely helps.

The Union of Concerned Scientists has done a study that shows how EVs are better for the environment. Cleaner Cars from Cradle to Grave | Union of Concerned Scientists

In my opinion, the future of clean energy won’t be solar, nuclear, hydro, or wind. It will be heat mining. https://energy.mit.edu/news/underground-heat-an-omnipresent-source-of-electricity/

For geothermal power stations are confined by geography. It needs an area where there are hot rocks not far underground. Iceland is famously volcanic and has such power plants. But the population of Iceland is…366,000. For that power to be exported to other countries with larger population centres and so large demand for clean power will it require an undersea power cable. This is an expensive undertaking, but there are plans to do this. It has been talked about for many years and a power cable between the UK and Iceland would be the longest undersea power cable in the world. It may happen because a cable between Norway and the UK has just been completed, so the costs and difficulties are better understood. Subsea power interconnectors avoid a lot of the legal issues that plague land based cables, but they are a substantial investment. An alternative is site power hungry businesses close to geothermal power plants. Iceland have done this. District heating, Aluminium smelting plants and now power intensive data centres.

However, there is another technology that is based on the same principle, but on a domestic rather than an industrial scale. That is ground heat pumps. Bore a hole in the ground, pipe cold water in and get warmer water out. Just running a pipe under your garden can be viable, but a borehole is a better.

There is a lot of interest in this technology to solve the dependence the UK has on natural gas for domestic heating which creates a lot of C02. It is a technology for the colder climate. Sadly living in apartment, I could only retrofit an air source heat pump, but they are expensive. Hopefully the costs will come down or there will be a government incentive.

Reducing energy consumption to heat buildings is an important part of the equation. An alternative to building more power stations and electricity grid upgrades.

But if you live in a place where the main concern is getting rid of heat…that is a different problem.

You have responded with a good overview of geothermal power and how it is conventionally harnessed. However, "heat mining” is taking new drilling technologies derived from the fracking of oil and drilling 4 or 5 miles (on average) down to a point where the molten core of the earth could heat water above the boiling point. Thus allowing the heat of the earth to power a steam generator. Yes, it is cheaper in areas where the volcanic activity is closer to the surface (as in Iceland), but the MIT study proposes that this could be done on 80% of the land mass of the USA. The small footprint of such a facility would allow for the production of a multitude of such power stations.

This company working in upstate New York sells “affordable” geothermal installations to replace existing HVAC systems. I use quote marks because I have no idea what they consider affordable. And of course, this isn’t providing electricity, just heat or cold.

There is an experimental geothermal power system at the Eden Project in the South West of England. There is no active volcanism in the UK, but the geology of this area is granite.

They are drilling two boreholes down to 4.6Km and water is pumped down one cold and comes up the other hot enough to run a turbine and produce about 5MW.

They also make the claim that it could be done almost anywhere. I guess that is always the case, if you drill deep enough. But they seem to be taking advantage of a known fault line.

They are careful to make clear that this is not a fracking technique, which has a bad name in the UK and they are putting seismic monitors on the site to detect any tremors.

The Eden project is a series of heated domes that re-create various ecological environments and it uses a lot of natural gas. It is a big tourist attraction. The UK Prime Minister, Boris Johnson, has paid a visit. He is keen on low carbon technology and innovations such as this. Hopefully this is a bit more credible than his Blue Hydrogen/CCS projects.

I am skeptical, some geothermal projects get thoroughly clogged up with mineral deposits fouling the pipes. They are also drilling through hard granite, which must be challenging. If they need a suitable fault line, then the claim that they can do this anywhere is perhaps overly optimistic.

But we shall see.

I wonder what it cost to drill down that far. And what’s the overall cost of the system; does it produce electricity at market rates?

There are some funding figures on their blog. But so far they have drilled one well and will run it like that for a while to generate power and takes lots of measurements. Then later drill the second well to complete the design.

It is an experimental project. I guess part of that is to inform the business case for further projects. I guess there will be some kind or report once it is complete that shows whether it is financially sound.

They are drilling through granite, which is pretty hard and must be more expensive than regular sedimentary rocks.

The obvious problem is the size of the “radiator” and the speed at which heat conducts through the ground at the levels involved. Overdrive the heat source and you end up with a zone of cooled rock and have to wait for the heat to catch up.

I knew a couple that used a heat pump for their cabin (then decided to move out there year-around). Instead of drilling a hole, the ran the line down to the lake (benefit of lakefront property) and then threw about 100 feet of feet of tubing into the lake. If those coils are deep enough in the lake, are below the ice, the entire lake will stabilize about 4°C. Unless you freeze the whole large lake, you have a good heat source that stays no colder than that. Spread out the coils of pipe, and when the pump is not running, any ice buildup will come off (or run the pump such that it does not run the coolant below freezing?) Not sure the details, but apparently it worked and was more energy-efficient. Plus, they were not on a natural gas feed, so even better, since electric heat would be worse.

Heat sinks are an interesting answer to improved efficiency heat pumps. In very cold climates they probably offer a much better answer than heat pumps sucking on cold air. In some areas you can get the best of both worlds, cooling your heat sink in winter, and heating it up in summer. I looked seriously at this option where I live, but the prices for installation were pretty steep, and since we don’t have really bad extremes of temperature, the numbers didn’t really work. I have seen COPs for systems in excess of 6, which is a huge win. For a year round heat sink I have seen numbers like 2 million gallons of water will cope with a households annual cycle. Sadly a bit bigger than a domestic swimming pool.

Geothermal, as in hot rocks, was a big thing here a decade ago. The trick with these was to find a nice huge lump of granite that is sitting in a more insulating strata. Over time the natural radioactivity in the granite will heat it up. A well drilled into the rock lets you flow water through it and harvest energy. But the harvesting outruns the radioactivity, so your well will go cold. The idea was to drill a set of wells and cycle though them, leaving a cooled well a decade or so to heat up again. But there are real difficulties in implementation. Running really hot water at pressure through any rock is going to result in having to face geochemical processes. And really hot high pressure water is what gets you your thermal efficiency when it gets back to the surface.
Your rock will dissolve and precipitate in unwelcome ways. The passage ways that the water flows though have a habit of blocking up, and the system fails. The cost of remediation can exceed your profits, and the whole thing may turn out not to be viable. Which is a pity.

Just as a bit of trivia, California produces more geothermal energy than Iceland. The Geysers produced 6516 GWh of electricity in 2018; Iceland produced 6010 GWh in the same year. Of course, Iceland is tiny and they get a higher fraction of their energy from geothermal (and probably have greater theoretical capacity as well).

This is done on a large scale in downtown Toronto (for cooling, not heating): the Deep Lake Water Cooling System.