What should the UK energy policy for the next 25 years+be

rogerblack

Martyn1981 wrote: »

I think batteries might be breakeven now,.

Purchased - with warranty - batteries are not breakeven.

All of the batteries I've found so far have a rated capacity * charge cycles of about the same cost as normal rate electricity.
(around 10p/kWh).
This neglects the fact that charge storage has losses.
May second hand batteries work OK - certainly.
For how long is another question.

zeupater

rogerblack wrote: »

Purchased - with warranty - batteries are not breakeven.

All of the batteries I've found so far have a rated capacity * charge cycles of about the same cost as normal rate electricity.
(around 10p/kWh).
This neglects the fact that charge storage has losses.
May second hand batteries work OK - certainly.
For how long is another question.

Hi Roger

It could be possible to better cost justify if you were a very low user on a tiered electricity tariff because the saving would be nearer to 20p/kWh than the 10p you mention ... it's still marginal though, depending on the cost of the control system.

Our electricity usage 12mths to end Jan'13 was a shade over 1350kWh, of which close to 900kWh is at tier1 pricing ....

HTH
Z

Cardew

It is not just the cost of batteries, Health and Safety regulations on charging/storing batteries are quite extensive - particularly regarding ventilation.

http://www.hse.gov.uk/pubns/indg139.pdf

You really need an outside building, and some nice thick cables to reach inverter.

EricMears

rogerblack wrote: »

Originally Posted by EricMears
But "Grow your own" seems even more attractive. Slight snag is that we'd all need to work out a procedure for safely de-linking our inverters from the mains whilst a power cut is in progress

Unfortunately, batteries are both expensive and unreliable.
Yes, you can get enough batteries to carry the average house over the daily variation.
These will cost perhaps £1-2K, and will last 5-10 years.
They might even let a house - in the summer - be energy independant.

Afraid my point has been a bit misunderstood.

I wasn't suggesting that we should store our own electricity for use during power cuts but was bemoaning the fact that during any outage the inverter powers down. That happened to me on what was probably the sunniest day last year :mad:


It's theoretically fairly easy to switch off grid connection then convince the inverter that a temporary power supply (either from a small inverter designed for using mains equipment in cars or a purpose built UPS) means that power has been restored. Your 'toy inverter' then allows you to use the 4kW (or whatever) that your SP would provide - and by way of a bonus lets you keep earning FITs.

Last year's power cut took me by surprise so I wasn't able to set that up in time. Expectation of more frequent outages would be something of an incentive.

rogerblack

EricMears wrote: »

It's theoretically fairly easy to switch off grid connection then convince the inverter that a temporary power supply (either from a small inverter designed for using mains equipment in cars or a purpose built UPS) means that power has been restored. Your 'toy inverter' then allows you to use the 4kW (or whatever) that your SP would provide - and by way of a bonus lets you keep earning FITs.

This is unlikely to work.
Certainly - the grid tie inverter will notice mains voltage, and start generation.
Once the generation exceeds the load on the inverter (if, for example, you're running a 100W lightbulb), various things will happen - from the UPS shutting down (followed by the inverter) to dying permenantly, to requiring an amount equal to the generated power from the batteries, and then shutting down.

To actually get a grid-tie inverter to work 'islanded' - is annoyingly complex - as you have to both defeat protections to get it not to do this, and have some mechanism for on a moment by moment basis absorbing all the generated power, so it doesn't trip off due to over or undervoltage.

zeupater

rogerblack wrote: »

This is unlikely to work.
Certainly - the grid tie inverter will notice mains voltage, and start generation.
Once the generation exceeds the load on the inverter (if, for example, you're running a 100W lightbulb), various things will happen - from the UPS shutting down (followed by the inverter) to dying permenantly, to requiring an amount equal to the generated power from the batteries, and then shutting down.

To actually get a grid-tie inverter to work 'islanded' - is annoyingly complex - as you have to both defeat protections to get it not to do this, and have some mechanism for on a moment by moment basis absorbing all the generated power, so it doesn't trip off due to over or undervoltage.

Hi

Or, optionally, annoyingly expensive ... ( http://www.sma.de/en/products/battery-inverters/sunny-island-60h.html )

HTH
Z

Energetic_2

http://www.guardian.co.uk/environment/2013/feb/19/cannot-afford-nuclear-power-energy-mix

Martyn1981

zeupater wrote: »

Hi

Or, optionally, annoyingly expensive ... ( http://www.sma.de/en/products/battery-inverters/sunny-island-60h.html )

HTH
Z

There seems to be quite a few of these type products arriving now.

One I saw included a Lithium battery with a 20 year life expectancy, but cost around £8k. So that's £400pa to break even, before considering cost of capital etc. I suppose it depends on how much of the cost is the batts, but even then, after 20 years, the rest of the kit may need replacing too.

Presumably this will drop, but I'm not holding my breath.

@ Roger, bit confused on your breakeven point, did you mean batts breakeven at 10p, but only if you ignore the losses? If so, then that's where I was coming from, but had rolled the 25% losses into an unit cost of about 12p to 13p. So same idea, different direction. However, as I said, no point till leccy costs more, perhaps 20p, because of the rest of the kit, and a shame to waste leccy (in the storage / retrieval process) that could be exported instead.

Mart.

rogerblack

Martyn1981 wrote: »

@ Roger, bit confused on your breakeven point, did you mean batts breakeven at 10p, but only if you ignore the losses?

Yes, sorry I wasn't clear.
It does not make sense at this point in a real world situation undistorted by 'free' power from subsidised solar.
If, of course you can get grid.
If you can't - it can be not _horribly_ more expensive than grid.

Martyn1981

rogerblack wrote: »

Yes, sorry I wasn't clear.
It does not make sense at this point in a real world situation undistorted by 'free' power from subsidised solar.
If, of course you can get grid.
If you can't - it can be not _horribly_ more expensive than grid.

Cheers. I did try to work this out a year or so back, just for nightime baseload, but just the batts came to about £1k, with possible savings of £100pa. Apparently if I knew what I was doing (which I don't) the batts could last 10 years, so dead in the water unless leccy prices go up. So no gain, plus 25% wasted leccy. Also told "most batteries don't die a natural death, they are murdered".

Just thinking out loud, but if each house had storage for 2kWh's, then I think that works out at about 20GW reduction in demand for 2 hours (5 to 7pm). Appreciate that would be a nightmare, but could localised battery storage work instead, say 2MWh's per 1,000 properties?

I appreciate that the cost would be massive, but savings in constructing power plants to meet maximum, and could be charged from excess renewables and nuclear throughout day or night as capacity increases.

I'm guessing this is a non-starter but have read of research into large scale batts, particularly ones that charge then store liguid electrolyte.

Mart.