From Ars Technica
Optimizing battery use to minimize emissions is possible, but generally overly expensive.
Megan Geuss – 12/28/2018, 4:59 PM
A Tesla Powerwall 2.
Another year, another reason to take the promises of residential home batteries with a grain of salt.
This month, a group of researchers from the University of California San Diego (UCSD) published a paper in Environmental Science and Technology reporting that there are very few cases in which operating a residential home battery reduces overall emissions—assuming that households are economically rational and trying to minimize costs.
Of course, if the battery is only discharged during periods of peak emissions and only charged when fossil fuel use is low, then a household might reduce emissions. But across 16 representative regions, operating a battery this way ended up being costly.
The results are similar to those published in Nature Energy in the beginning of 2017, although that study looked at a narrower region (99 homes in Texas) and modeled different battery software configurations.
The UCSD study looks at representative homes under 16 different utilities across the country. Each utility has its own emissions profile and unique demand requirements (depending on the weather in the region). The study also looked at three different configuration possibilities:
- A demand-shifting configuration, where the battery is used to minimize costs when electricity rates vary by time of day;
- A solar self-consumption configuration, where the user has solar panels and wants to maximize the amount of energy they get from those panels; and
- An energy arbitrage configuration, where the residential battery owner can buy and sell electricity at retail rates depending on what’s cheaper at the moment.
Further Reading
Want to minimize your home’s carbon footprint? Go for solar, forget the battery
All of these configurations are a little futuristic but still representative of shifts that are happening in the electricity industry today. While most people don’t have time-of-use pricing, it’s becoming more common (this author’s household is charged time-of-use pricing) and it will become the mandatory rate structure for many households in California in 2019. While most solar panel owners prefer not to maximize self-consumption because it’s more cost-efficient to sell electricity back to utilities under net metering, utilities have been pushing back on requirements to buy back solar power from residential customers. The energy arbitrage configuration is the most futuristic, and “reflects the vision of advocates of decentralized energy management,” according to the researchers.
Environmental Science and Technology
The researchers found that the only way to reliably decrease emissions using batteries is if utilities incorporate a “Social Cost of Carbon” into their pricing schemes—that is, charging people extra for using electricity during carbon-heavy periods of generation. This helps bring batteries into the emissions-reducing fold. Unfortunately, including a cost for carbon dioxide emissions has proven politically difficult.
Environmental Science and Technology, 2018. DOI: http://dx.doi.org/10.1021/acs.est.8b03834 (About DOIs).
HT/Latitude
Please ignore last comment, I was looking at the wrong article.
Nuts to CO2 emissions. Follow the money. I have solar. In the UK, my utility company charges me 3x as much per unit as it credits me for each unit deemed exported to the grid (there is a government bribe, err incentive, on top of that which makes rooftop solar economic).
Being a lithium battery fan, I have of course considered battery storage. However my solar array is not big enough to make battery storage sensible at these northerly latitudes. I only produce a few units a day, so any time shifting capability needs to have low capital costs to make it viable. Cost for new batteries is too high at present.
That may change if two things happen. Firstly. if efficiency of solar panels improves to the point that I can produce a goodly proportion of our daily consumption even in winter on a cloudy day. Secondly if a market develops in second life EV batteries. For an EV, battery capacity is critical. For this application who cares if capacity is down to 80% of the original? If you don’t have enough capacity then (metaphorically) raid the scrapyard for another used battery.
A final note. Of widely-available chemistries, lithium ion is the best fit: partial charge and partial discharge suits it very well but lead acid prefers to be fully charged regularly
You have to understand the logic that drives the idea of the residential battery.
The Party Line consensus on Ars is that we are heading for a gobal warming disaster. So naturally the hand picked commenters look feverishly for solutions. The Party Line is that renewable energy for electricity generation is a big chunk of the answer.
This is because renewables appear to give the hope of limiting emissions without serious changes in lifestyles. We will continue with the freeways and suburbs and air conditioning, it will just be powered by wind and solar.
It then becomes necessary to have batteries to power all those electric cars which are going to be plug in replacements for ICE. Spearheaded by the immortal Musk and the great Tesla Corp, which is obviously the future of transportation.
And on generation, Ars is caught in a dilemma from which batteries are an escape route. On the one hand it wants to claim that their intermittency doesn’t matter in modern grids. In some unexplained way, its supposed not to matter when the electricity is generated. There is no longer any need to match supply and demand. Yes, you will actually get a chorus of assertions of this if you read the comments. People really do claim to believe this.
They are then able to argue for Levelized Costs as a comparator. The Party Line at Ars is that fossil fuels are economically dead, because renewables are now cheaper. To support this position they have to be one of the few places in the world defending the use of Levelized Costs as a measure of comparison between different generating technologies.
In order to make this even halfway plausible, you have to believe in free or cheap storage, and if you can manage to believe that everyone is going to install residential storage batteries powered by wind or solar, you would be sort of home free. Because then you do not have to add storage costs in the grid, which, if you do, immediately takes the cost of wind to well over double that of fossil fuel generation.
It makes absolutely no sense. Its impossible to summarize without seeming to parody it. Its full of contradictions and non-sequiturs. But this really is the Ars Party Line. If you have to summarize it in one line it would be something like this:
Intermittency is not a problem and batteries are the solution to it.
The fact that this relatively common sense and specific piece has appeared, correctly pointing out that residential batteries are not the solution to anything, is a very interesting sign that maybe the owners of Ars, Conde Nast, are waking up to a need to back off from the Party Line. Another sign is their interesting lack of coverage of the latest IPCC material.
Pretty soon we will always have been in favor of thorium, or fusion. And CO2? Oh, that was so millennial!
The central thing to notice in order to understand the social phenomenon of global warming hysteria is this.
The measures most fanatically advocated will make no significant impact on the total of global emissions. And the measures which would make such an impact are not simply never advocated, if proposed, they are furiously rejected.
Example of the first: Paris, installing wind generation, electric automobiiles. Example of the second: actual tonnage reductions from China and/or India, Indonesia etc. Global abolition of the ICE.
Think long and hard about what could be the most likely cause of this insistence on advocating things that can not work, while refusing to advocate things that would.
I’ve published a study of the poor economics of using battery storage alongside roof-mounted solar generation in the UK.
https://www.thegwpf.org/content/uploads/2018/04/Aris2018.pdf
Excellent analysis.
Well, Capell, your published study addresses the life-cycle economics of residential battery storage without any consideration of the actual energy storage and use inefficiencies of the system.
Caveat emptor . . . it is worse than you concluded.
That was the objective of the paper, to stop people donating money to solar/battery-storage spivs.
As for the system at large – well that’s an even bigger mess. Right now Gridwatch is quite entertaining: all the nuclear, CCGTs and coal flat out, solar and wind delivering precious little, Netherlands interconnector at zero, Ireland taking half a gegawatt, and UK load rising . . .
Sorry, I’m struggling to wee what they’re talking about.
My take on it is that ‘some’ folks might install a battery to fill with cheap electricity then re-sell it later when prices are high.
No mention of solar panels or consumer generated power APART from here:
Then inside that quote, they misunderstand what net metering is – you DO NOT sell surplus electricity under a net metering scheme. You give it away and let your meter run backwards. Then at month-end, you only pay for what you actually consumed/used.
Net metering here:
https://searchcio.techtarget.com/definition/net-metering
So installing a stand-alone battery (without solar panels of your own) as they seem to be saying is no more than playing on the stock market or gambling in a casino.
And every time you place a deal or a bet, you lose 10% of your stake through battery & conversion losses – even before the utility and/or Government move in for a piece of the action.
Quite insane. Why would anyone do it – You Are Going To Lose.
You are up against Professionals who know what they’re doing = Making Money and they will milk you.
Making Money is what they do. Electricity supply is entirely incidental to that
wee
cracks up with tears in eyes
wee = ‘waste electrical equipment’
What a beautiful Freudian – I amaze myself sometimes
In the UK solar rooftop generation is not economic without subsidies. If costed correctly, with discounted cash flow analysis at sensible rates, the payback period stretches to between 15 and 20 years – good luck with that. Adding a battery to this financial disaster just increases the financial loss.
https://www.thegwpf.org/content/uploads/2018/04/Aris2018.pdf
But of course, they’re great bragging rights at London dinner parties.