Energy infrastructure

There was a section on renewable electricity in the Economist last week. There were some interesting stuff that I was not aware of -

For the past years, in developed countries anyway, the electric grids have been more or less static. This means that the large suppliers have managed their supply based on replacements only (ie a new transformer would only be needed when an existing one reached end of life). Now as a result of renewables, the grids are growing rapidly and the suppliers are not able to keep up with demand. A large scale transformer which weighs 300 tonnes, costs 30M euros takes 3 years to supply from order to delivery. And while suppliers are expanding existing plants more productive, they are not willing to build new capacity as they see this as a one off spike in demand. This is in the early days of renewable electricity demand spike so the deliver timescales are likely only going to get worse.

The other one was about interconnectors and how current technology limits their use. Most interconnectors are HV DC, this is then converted to AC at the receiving grid and it is vital that this is synchronised with the local grid frequency. The local grid frequency is controlled currently by spinning metal (the large drive shafts in power stations that spin at 3000rpm). Invertors are used to convert the DC to AC but these are mainly "grid following" so it is important that there is enough spinning metal in the grid otherwise things can get out of sync. The next generation of invertors are "grid generating" so that they can be programmed to synchronise with the grid and the need for spinning metal is redundant. Using these in conjunction with the new power transistors means that it will be possible to route the power to where it is in most demand so for example a wind farm in the North Sea that typically sends power to Scotland, could instead send it to Germany if there was no demand in Scotland. This would of course require that the wind farm had an HV DC interconnect to Germany.

The result of all of this is that the expansion of the grid demanded by decarbonisation is the biggest change to power systems in history.

It doesn't really matter if residential PV is more expensive than utility PV. The big advantage is that the homeowner is the one investing their capital rather than the government or an institutional investor. So while the cost is higher per kW it's a new source of investment.

If residential solar also reduces demand that EVs put on the grid it will likely reduce the need to upgrade the distribution grid in many urban areas. This will have a large positive for folks like ESB Networks who manage distribution.

Looking at a country like the Netherlands, which is adding tons of PV, you can see that residential solar is adding a meaningful contribution: https://www.iea.org/data-and-statistics/charts/netherlands-solar-pv-capacity-additions-2018-2022-and-average-annual-additions-2023-2025

Residential solar rarely takes resources from utility or commercial solar installation pipeline. It's different capital, it's different installers, and it's a different planning process. They are both using similar panels, but the commercial/utility folks are using different inverters etc. Panel production is not really an issue TBH.

Comparing them isn't really that useful because they aren't really competing with each other.

it is not correct to say that Solar will reduce the requirement for grid upgrades. It will not reduce the peak winter demand by one iota.

If more then a third of homes get PV and export during peak summer months, upgrades may be required to deal with this PV export

The cost is undoubtedly higher and this higher cost is ultimately paid for by the consumer (electricity bills and capital repayments) and the taxpayer (tax breaks and grants).

That is not to say that we shouldn’t have lots of residential PV but it is important to understand that it is relatively high cost, and low return as a result.

Batteries are a different story.

Yes 46c/kWh is serious differential! Batteries are sustainable when it goes over 10 or 20c from memory.

Most people would want a supplier or similar to commit to this type of rate over a sustained period to make it a good investment.

Peaks are is in the winter months in the hours after the sun sets. This is when energy gets really expensive on windless days. Solar won’t help with this at all.

I don’t see how solar will reduce peaker demand. It will mostly offset CCGT demand.

it will make no difference to the total infrastructure required to support the winter peak as you rightly say. This goes for peaker plants as well as distribution and transmission assets.

This still has to be paid for out of customer bills.

Re transmission/distribution costs, we are speaking at cross purposes. I am speaking about charges. Setting the afternoon charges to 0 or 1c/kWh (and having a high peak charge to compensate) would still collect the same amount of money but it would make domestic solar far less attractive.

Fracking isn't stationary technology ,it's moved on a hell of a lot on the last 10 years , and is a lot less damaging than it was in the early days , I'm sure it still has problems but it's a lot better than it was ,

Also a lot of shale gas is a by-product of shale oil production , if they don't sell it ,it gets flared on site , so burnt without doing any thing

Apart from the fact I don't think we have any large shale gas basins here ..

Could better grants be offered for solar for a more spread pattern of generation ?

So either with a battery , east and west facing panels or tiltable panels so that it's not huge peaks around mid-day ,

It'll be interesting with electric cars as well , if your car is at work but your panels are flat out producing at home you'd be a bit miffed - especially if you had to buy a second huge expensive battery to overnight charge your ev , when its off peak from the grid,

Suddenly a reasonable mid day feed on tarriff combined with a cheap off peak use tarriff doesn't seem so bad

No - peak oil theories always referred to something that was going to happen decades into the future.

The change in energy markets is already clearly visible in the numbers. Fossil fuel consumption has more or less levelled off in the last ten years:

For perspective, the previous century looked like