Future battery tech for solar PV

celerity

Thanks to this forum, I spent an enjoyable afternoon yesterday being paid to be interviewed about solar PV .

Without going into too much detail, the focus was on a proposed battery system for new installs. If it works as implied, this would have a smart controller to divert any unused energy during the day to a battery pack which would then be used seamlessly throughout the house during the evening.
Whether it would serve as an off-grid backup during a power outage wasn't clear.

If this is the way forwards for solar PV I would personally be extremely positive. It would solve the main problem with domestic systems, in that energy wouldn't be wasted during the day.

Obviously the main factor would be the price of the battery pack and controller.

/\dam

Martyn1981

Adam. Is it (was it) along the lines of the 'grid-buddy' discussed here:

https://forums.moneysavingexpert.com/discussion/3819869

these techy guys don't seem too impressed, yet.

http://www.navitron.org.uk/forum/index.php/topic,16936.0.html

Early days I guess, but the future does seem to be getting closer, slowly!

Mart.

celerity

It is similar, but the difference in my opinion would be in business rather than technological terms. The manufacturer is a major player in the panel market themselves, so I could see this being positioned in the marketplace as a "standard" installation option.
In other words, if this manufacturer decided to push it in a big way, they would have the resources to get installers on board fairly quickly.

It would then be a relatively simple matter of spreadsheeting the costs and proposed battery capacity and looking at the payback period.

I got the distinct impression this isn't even at the prototyping stage yet though - it was a market research survey after all.

As an aside, and this is my opinion only, I think this kind of system would be harder to retrofit as most standard PV installs don't have wiring conducive to easily working out the surplus energy available in the property at any given moment. So I reckon it would be a cheaper option during a new install phase.

If it did become available, and the numbers stacked up, I for one would try and launch a campaign on here for us to team up geographically and see if we could get discounts on a retrofit from the same installer .

/\dam

celerity

...also, looking more into GridBuddy, my impression is that they are utilising existing components - I'm assuming the system I was polled about would be new technology specifically designed for <=4kWp domestic systems.

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celerity

One thing that wasn't made clear to me was whether the existing inverter would need to be replaced. If that was the case it would make a retrofit even less viable.

/\dam

rogerblack

Speaking as someone from the electronics side - at the moment, batteries are the problem.
There are basically two ways to do this.

Either you have a battery that sits on the solar-panel side of the inverter, and is controlled to only absorb power as needed to make the export zero.

Or, you have a battery that plugs into the mains, and is similarly controlled.
The latter is less efficient and more expensive, but the former potentially raises MCS issues, and is harder to install.

It's technically not a hard problem - either part - the hard part is the batteries.

Currently, a battery bank is worn out by quite a bit more than 17p/kWh for batteries that can be cycled every day.

Which means that it will not actually save you money, with current technology.

At the moment, production of various sorts of batteries that might work is ramping up for electric vehicles, but this app is even tougher.
What you really want for cost reasons is a battery that can do around 3kWh/day, which would - with the panels during the day - cope with the majority of nighttime loads in a minimum house.
With current batteries 2000 quiddish is going to be challenging to hit, and it's going to die in 5-10 years.

However.
Solar is beside the point.
I want one of these, and to go to economy 7.
Never buy any peak-time power.

Cardew

rogerblack wrote: »

However.
Solar is beside the point.
I want one of these, and to go to economy 7.
Never buy any peak-time power.

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.

rogerblack

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.

Eventually, yes, for a start, it would make sense eventually for electricity companies to build massive smoothing banks.

EricMears

rogerblack wrote: »

Eventually, yes, for a start, it would make sense eventually for electricity companies to build massive smoothing banks.

Suspect that "When battery technology gets cheap enough" will pretty well coincide with a plague of porcine aviators and hell freezing over !:beer:

grahamc2003

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?

celerity

*grins* at Graham