Random Renewables Thread

They wanted to build a Nuclear power station when they couldn't build a bypass at Kinnegad. No hindsight required, I laughed as loud at the idea back then, as I'm laughing at it now.

Speaking of installation times, 488MW of solar and 186MW of wind was installed in 2023 in Ireland

Let's call that approximately 20% of Hinckley Point C (3,200MW) which has been under construction since 2017 at an estimated cost of £35 billion (in 2015 prices). It's projected that construction will finish in 2029 at the earliest

So in the 12 years of construction, they could have installed 2.4x the equivalent capacity of renewables

I don't know how much that would cost, but I'm going to throw out a guess that it'll be a lot less than £31 billion

Still think nuclear is the way to go? 😉

"So in the 12 years of construction, they could have installed 2.4x the equivalent capacity of renewables"

Things don't quite work like that.

Things like wind and solar are immensely scalable. Most of what is involved in building them is ordinary construction work - excavating / filling, installing steel reinforcement, pouring concrete, laying ducts with cables. You then have a team show up with the large, factory-made parts of and fit them. Admittedly, wind turbines need specialist transport and cranes. There is an established industry. The work can go on at many sites or many parts of a site at the same time.

With a nuclear power plant, you don't want just about anyone doing the work and subcontractors doing short cuts. It all has to happen on one site, and that create practical limits.

The RoI on domestic solar batteries doesn't add up. Even with a 20c difference between import and export and a 10 to 15% full circle efficiency loss, you will barely cover your capital costs, with no allowance for maintenance or risk. It might work on an industrial scale when cost per kwh of storage drops.

Oh yes it does. Even on a domestic scale. Even today. Depending of course on what you pay for your install. Presuming you already have a PV install with a hybrid inverter but no battery yet and you have a smart meter and you qualify for FIT

A 15kWh battery costs about €1000 + VAT in cells plus some cables and a €100 BMS to DIY. Just to do a simplified sum. Charge it up every day at 5c and dump it into the grid at 25c, with 20% round trip losses. This makes you:

365 days * (€0.25 - €0.05) * 15kWh * 80% = €876, or a pay back period of less than 2 years and that is from night charging and dumping alone

My own electricity bill is already negative for the year, and that includes running 2 EVs, heating all my hot water and doing some home heating with electricity

In future, the delta between buying and selling will often be much higher than this €0.20 as you can see from countries a bit further ahead than Ireland with flexible tariffs, like the USA, the UK, the Netherlands, etc.

I agree with you though that if you get an SEAI company to install a pre made 5kWh battery and they charge you €3000 for that, it will not likely ever pay off in the current tariff situation

I may be corrected on this but I think a 9kW heat pump with a COP of 3 will only look for 3kW of electricity from the grid.

The 9kW is the heat output, measured in Watts instead of BTU for some reason.

There was a significant amount of grid scale battery storage installed last year. I remember reading an article that Ireland topped the amount of battery installation in Europe for 2023, so it must make sense to someone

I agree that we'd need backups for days with poor renewables, but that's one area where nuclear is truly awful. It doesn't exactly throttle very well, and even France needs a lot of gas turbines for peak power demand.

France actually has significant interconnectors with Germany because they're often overproducing nuclear in summer and need to shed excess electricity

In the case of Ireland, batteries and pumped hydro would definitely help. We'd probably need some thermal plants as backup, but if they could be supplied with biomass or biogas then at least it isn't fossil fuels

More interconnectors to UK and France would definitely help as well by giving us access to their electricity markets

That kind of misses the point however, even if there's a percentage of thermal generation in the mix, a large amount of renewable generators would push us much higher than 35% green electricity in 2023.

If we manage to get to 70% or even 90% during good days we could be using cheap electricity to process biofuels and stockpile fuel for winter months

Yep, I've never seen my 6kW heat pump consume more than 1.6kW of electricity

It does have a separate backup heater which is effectively an immersion heater and can draw 1.5kW I think

That only comes on the off time though

I did notice the heat pump is on a 20A fuse which could supply up to 4.6kW. I'm guessing that's to handle the startup load of the motor spinning up since there's nothing else on that circuit

I suppose soft starters might become a requirement where the grid is constrained to stop a noisy demand curve

<rant>Ireland needs trees not grass. The Irish have an obsession with cutting grass (more so than the English). I know when the English were here, you couldn't get a job off them unless you were clean shaven, smartly dressed and could cut grass 24 hours a day on the English estates, which is why everyone in my nearby village still shaves until they bleed (including the women), are smartly dressed and cut their lawns if they so much as grow more than 1mm.

I never touch beef. I can do without milk. Cull all the cattle and give Ireland some lungs with millions of trees. Windfall wood is enough to run my stove. I never touch a growing tree.

As mentioned above, there's no joined up thinking. Household batteries for all. Wind farms along the entire west coast. NZEB building from now on. Embrace population decline until (and only until) it's critical then provide financial incentives to breed or baby farms, if the snowflakes no longer enjoy such things.</rant>

When I was considering heat pump for my own house, the amount of friends and family that misunderstood that power rating was shocking. Installers and manufacturers could do with making it more prominent that it is output not input.

Microinverter?

The issue was only with Deye microinverters. They now supply an external relay.