Future battery tech for solar PV

EricMears

grahamc2003 wrote: »

But what if the government came up with a Battery Feed In Tariff, which rewarded people for each kwh of energy they stored in a battery? Say the subsidy typically gave a return of £1500 for those spending £10,000 on a battery storage system.

If it was a one-off payment of £1500 then it would have very few takers.

Were it an annual payment then I'm sure we'd all snatch their hands off.

However, the schemes worked for solar panels because they were a newish technology that needed an influx of early adopters to create economies of scale (probably not many of us remember early colour TVs with indifferent picture quality that cost the thick end of a years wages but a similar scheme wuld have worked then too).

Storage batteries are an ongoing technology that's been 'under refinement' for many years and there are already practical incentives for further advances without needing such a 'spur'.

grahamc2003

EricMears wrote: »

However, the schemes worked for solar panels because they were a newish technology '.

I suppose 'newish' is a relative term, but solar power was first used by the ancient Greeks about 700BC.

If you are talking specifically about PV, then the effect was discovered by Becquerel in 1839, and I expect has been in development ever since.

Even pv on roofs goes back at least 60 years, and I have just dug out an old academic text used for undergraduate education on solar pv dated 1974.

I wouldn't say it's a new technology at all.

EricMears

"Newish" seems a perfectly reasonable way of describing a technology that wasn't until recently very widely used.

I wasn't aware that the Ancient Greeks actually had a grid system, AC power or even electric lights ! Becquerel's discovery had little practical application at the time and sixty (or even ten) year old PV installations were far from economic so could only be justified in very special circumstances.

Hard to imagine Telstar working with a very long extension cable of course but that sort of application would never have resulted in the huge economies of scale we're now seeing.

celerity

(I'm in no way arguing with Graham here, just found this page interesting)

NASA wrote:

The first photovoltaic module was built by Bell Laboratories in 1954. It was billed as a solar battery and was mostly just a curiosity as it was too expensive to gain widespread use. In the 1960s, the space industry began to make the first serious use of the technology to provide power aboard spacecraft. Through the space programs, the technology advanced, its reliability was established, and the cost began to decline. During the energy crisis in the 1970s, photovoltaic technology gained recognition as a source of power for non-space applications.

Source: http://science.nasa.gov/science-news/science-at-nasa/2002/solarcells/

/\dam

John_Pierpoint

Cardew wrote: »

When battery technology gets cheap enough to make storing E7 off-peak electricity viable, you can bet the E7 tariff will be phased out - or the off-peak rate massively increased.

Isn't the problem the other way round:

The "greenhouse" climate change problem means we cannot use coal for the base load.

Nuclear is the "carbon free" [forgetting about all the carbon inherent in all that concrete containment] alternative.

You can turn down a nuclear power station, but you cannot switch it off.

So what will be desperately needed is MORE "Economy 7" usage, such as pumped storage ?

I fondly remember the days when the Nuclear power stations got so used to submitting a "striking price" bid for electricity supplies to the grid, that on summer holiday nights they ended supplying electricity to the grid absolutely free.

Anyone know how the French cope with their excess nuclear capacity in the early hours of the morning?

How about boosting crop production using 24/7 greenhouse food production using LED lighting - I think I can make my fortune by selling the kit to the urban farmers. :rotfl:
http://en.wikipedia.org/wiki/Cannabis_cultivation

Duration: 1–2 months indoors. In this stage the plant needs all the light (at least 18 hours) and nutrients (food) that it can use,
cultivators generally employ an 18- to 24-hour photo period because the plants grow more quickly if they receive more light, although a warmer and cooler period are required for optimal health.

The way things are going, it is looking like we are heading for "fracking" gas and using that to keep the lights on.

Martyn1981

John_Pierpoint wrote: »

Isn't the problem the other way round:

The "greenhouse" climate change problem means we cannot use coal for the base load.

Nuclear is the "carbon free" [forgetting about all the carbon inherent in all that concrete containment] alternative.

You can turn down a nuclear power station, but you cannot switch it off.

So what will be desperately needed is MORE "Economy 7" usage, such as pumped storage ?

Unfortunately, and much to my surprise, the UK doesn't have a lot of potential for further pumped storage. However, looking at the Desertec European Super Grid idea, Norway does have enormous potential.

Scotland is adding more interconnectors to Norway, but they are to import energy. Perhaps in the future, we could fund new hydro, or the addition of pumped storage to existing hydro in Norway, and use that as a battery.

Personally, I can't see any way around the problem of baseload that doesn't involve some nuclear. But nobody is going to privately build any new plants unless the Government guarantees that the output has to be bought. It looks like that output is going to cost around 10p+/kWh, and with falling renewables costs and commissioning times of around 10 to 12 years, that's a very tricky negotiation / gamble. Hence the second dash for gas at the moment, and the subsequent price effect.

Mart.

Cardew

grahamc2003 wrote: »

Looks like we mainly all agree that in the foreseeable future, battery technology is a very poor, expensive and non-viable technology for storing electricity from solar panels.

But what if the government came up with a Battery Feed In Tariff, which rewarded people for each kwh of energy they stored in a battery? Say the subsidy typically gave a return of £1500 for those spending £10,000 on a battery storage system.

Would the technology then be an excellent technology due to the financial returns of those investing in it, or would it still be a very poor and expensive technology? Would battery technology then get a great deal of public support even though it was still not fit for purpose by any sensible metric?

The Lithium-Ion battery in a Nissan Leaf electric car is 24kWh. More than enough to store sufficient power for the average house(excluding space heating)

The obvious problems are cost and and longevity.

Solve the problem of cost and it would be viable for storing all this Nuclear energy and many more battery cars would be sold.

Solve the problem of cost? Mmmm

grahamc2003

John_Pierpoint wrote: »

Isn't the problem the other way round:

The "greenhouse" climate change problem means we cannot use coal for the base load.

Nuclear is the "carbon free" [forgetting about all the carbon inherent in all that concrete containment] alternative.

You can turn down a nuclear power station, but you cannot switch it off.

You can turn them off, just takes longer than fossil stations. You can also turn them on again when you like - unlike windmills!

So what will be desperately needed is MORE "Economy 7" usage, such as pumped storage ?


Yes - any off peak usage is very valuable - in fact, the 'greenest'
thing the average Joe can do is to go to e7 heating. But everything is staked against that - it isn't sexy, so no support from the general public, and the government jst don't realise that is the case. Unlike in the nationalised days, there is no one proposing off peak usage. Nighttime electricity should be free imv - that would cause peak demand to drop and less new capacity to be built - probably cheaper to the uk as a whole.

I fondly remember the days when the Nuclear power stations got so used to submitting a "striking price" bid for electricity supplies to the grid, that on summer holiday nights they ended supplying electricity to the grid absolutely free.

I suspect you mean in the days of the electricity pool. Although the Nukes routinely bid 0 to generate, all generation was paid at the system marginal price (i.e. the max bid required to satisfy demand in a half hour period). So say Nukes bid 0p for 12:00 to 12:30 for 10GW, and the next lowes bi was Drax at £30/MWh for 1GW, 12:00-12:30, and demand was 11GW, then everyone would be paid at £30/MWh. (Strange market eh?)

Anyone know how the French cope with their excess nuclear capacity in the early hours of the morning?

They arrange for the Nukes to generate the demand and no more.

How about boosting crop production using 24/7 greenhouse food production using LED lighting - I think I can make my fortune by selling the kit to the urban farmers. :rotfl:
http://en.wikipedia.org/wiki/Cannabis_cultivation

Not my area, but surely for plants to grow they need light with the same energies and frequencies as daylight (which cointains a lot of energy). I bet plants under leds would simply think it was nightime and not grow at all.


The way things are going, it is looking like we are heading for "fracking" gas and using that to keep the lights on.

There's a massive expansion of very expensive small gas stations going on behind the scenes - 3GW has gone in in the last year (all co2 producing of course, not quite fitting the rhetoric of the government. But they are panicking, with no options in the short term, successive governments over the last 30 years fearing the anti-Nuke lobby - hence why we're heading towards more and more expensive electricity and powercuts). I bet there's a lot of crossed fingers in the government (if any understand the problem that is), that there's plenty of new gas to be had in the UK - I doubt in 5 years time we'll have the ability to bid at world prices for gas in the quantities we'll need it).

grahamc2003

Cardew wrote: »

The Lithium-Ion battery in a Nissan Leaf electric car is 24kWh. More than enough to store sufficient power for the average house(excluding space heating)

The obvious problems are cost and and longevity.

Solve the problem of cost and it would be viable for storing all this Nuclear energy and many more battery cars would be sold.

Solve the problem of cost? Mmmm

24kWh may be the nominal capacity, but I doubt the battery will last long if it is routinely charged fully then discharged fully. The Prius battery for example is 1.3kWh capacity, but to give the battery a life the same as the car (say 12/13 years), the state of charge is kept between 40 and 60% almost always (80% in exceptional circumstances. (On the battery display, zero charge displayed means 40%, and maximum charge displayed means 80%). There's only a max of 600Wh actual used capacity from the 1.3kWh available (equivalent to about a thimble full of petrol).

So it'll be interesting to see how long the Leaf batteries last (and how much a replacement costs!).

The Prius idea would work really well for PV. Instead of saving energy throughout the day, and releasing it through the night (the equivalent of the leaf operation), a PV battery could switch from charge to discharge second by second (like the Prius). Most things like washing machines could then be driven by solar with no import - e.g. when the washing machine is using 200w spinning and the solar gen is 1kW, 800w could be stored for some minutes - then when the heater switches in at 3kw say, 2kW could come from the battery for some minutes. The actual capacity of the battery wouldn't have to be all that much, but the charge and discharge rates would have to be high (again, like the Prius, with 21kW charge/discharge rate till temperature limits are met).

Most batteries and associated systems are still up against a 50% efficiency in and out, so saving 10kWh of solar energy would only produce 5kWh later in the day typically.

zeupater

Cardew wrote: »

The Lithium-Ion battery in a Nissan Leaf electric car is 24kWh. More than enough to store sufficient power for the average house(excluding space heating)

The obvious problems are cost and and longevity.

Solve the problem of cost and it would be viable for storing all this Nuclear energy and many more battery cars would be sold.

Solve the problem of cost? Mmmm

Hi

Following this discussion what really needs to be considered is what people really want to achieve.

Looking at our own usage, all that would be required to have a major impact on overnight usage would be the ability to supply a consistant ~300W over the average 'dark' hours, so, leaving out the deeepest part of winter when there probably wouldn't be enough pv generation to cover daytime requirements and charge a battery bank, we're probably looking at around a capacity of 2.5-3.0kWh, take out the inefficiencies of the batteries and allowing for a maximum 60% discharge in order to extend the battery lifecycle we're probably looking at around 6.25kWh of storage (3/0.8/0.6) ....

It would be a pretty simple solution to have a system which would charge from the mains when there was a surplus of pv generation and then supply back to the mains when there's a)enough charge available & b)insufficient generation .... the control system would, of course, need to disconnect from the mains when not available as pv inverters do, so what we're really looking at in engineering terms is the equivalent of a very small inverter and a reasonably small battery bank, say around the size of 6 110Ah deep cycle batteries, so a touch over £1100 (£500+(£100x6)) would be a reasonable cost/solution .... if the system doesn't supply the total household load when you turn the kettle on, or is pushing a couple of hundred watts excess back into the grid at times doesn't really matter as it is covering the baseload overnight an that's where the majority of our remaining usage is ... fridge, freezer, TV, low energy lights and some other low power devices ....

Payback ... well, if the batteries need replacing ever 10 years then that's currently £60/year .... if the system could save an average 2kWh/day at 12p/kWh that's £87/year (2x0.12x365), a marginal saving which just might see an eventual system payback if the inverter lasted 20years or so .... alternatively, averaging a 2.5kWh/day save at tier 1 electricity costs of around 18p/kWh would definately work for those currently with very low import levels (~1000kWh/y) if the saving is effectively doubled to £164 (2.5x0.18x365)) ...

Just my thoughts ....

HTH
Z