Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Household solar storage increases emissions, study concludes

This site may earn commission on affiliate links.
I don't fully believe it, but there are some big losses when it comes to this.

The AC <> DC conversion over and over looses energy and that's why people are also talking about having a DC network inside houses instead of just AC.

With DC you can:
- Run TV
- Charge laptop via USB-C
- Charge phone
- Charge a car

This power can come from a battery or PV without the need to go through a inverter.
 
  • Like
Reactions: dpeilow
This is a study published in a respected journal, its hardly clickbait FUD. However, its results are going to be mis-qouted and mis-used tremendously. If you read the actual journal article, What it is saying is that storing the energy locally is less efficient than sending that energy onto the grid where it can be used to offset fossil fuel based energy production. So basically its just saying that transmission losses to your neighbors are less than the storage losses, which is not surprising.

The article also notes that there would be tremendous benefit for utility scale energy storage.
 
When is household solar storage ever intended to reduce emissions? Never, I would think. It's about other things. Load balancing (sometimes ideologically for the utility's benefit), cost optimization (where net metering is not in effect), and/or backup power. A study saying it increases emissions in some cases comes across as just...some extra information, but only marginally relevant to whether or not someone should integrate a storage product with their solar.
 
  • Like
Reactions: miimura
The original paper is http://www.nature.com/articles/nenergy20171 The funding of the authors/institute include oil and gas and Koch. Analyze with care.

The study seems to show an increase in emissions for local energy storage due to increased emissions as other customers use the electricity which would have, instead, been transferred to the grid by local renewable power generation. Of course, that emission is no different than if there were no local storage. Explain again how this "increases" emissions? Cost comparisons in Texas are also a poor representation of typical costs in the US, as Texas has significantly lower than average consumer rates for electricity usage - $0.0863 per kWh vs. $0.1042 national average in 2015 (Source: Electric Data Browser (Electricity Data Browser) Energy Information Administration, Washington, DC. Nebraska Energy Office, Lincoln, NE.)

The oil and gas industry and the Koch brothers and their foundations and thinktanks have been lobbying to eliminate all renewable energy subsidies at both the national and state levels in the US for years. They have succeeded in states where their "conservative" partners control the legislature. They are lobbying the new federal administration to do so as well. I am sure their efforts have already begun in the new Congress.

And all this time, for some reason, they have never lobbied to eliminate the oil depletion allowance and other subsidies that the oil and gas industry has benefited from for over 100 years in the US. Last year alone, oil and gas tax credits and allowances were about $38 billion the US. The US government is picking the winner in energy generation by its tax policies and continues to, far and away, favor conventional fossil fuels. And they say "government shouldn't pick winners and losers . . ." :confused:
 
The original paper is http://www.nature.com/articles/nenergy20171 The funding of the authors/institute include oil and gas and Koch. Analyze with care.

Even a quick look at the school's website shows a very strong relationship with many oil companies.
2017-02-02 13_38_23-Corporate Partners - Cockrell School of Engineering.png


Readers must always use critical evaluation skills when examining "research" reports.
 
... If you read the actual journal article, What it is saying is that storing the energy locally is less efficient than sending that energy onto the grid where it can be used to offset fossil fuel based energy production.
So, does this study actually prove that solar IS better for emissions and costs for society and ratepayers? If so, then let's get to it! Utilities should be required to provide the cheapest and cleanest technology.
 
Household solar storage increases emissions, study concludes

Contrary to popular belief, household storage for solar power doesn’t reduce cost or emissions, an American study suggests...

I think the point is largely being missed. A better title would be 'If Demand is available then energy should be exported instead of stored'. Yeah... no kidding. The best round-trip efficiency of a battery is ~90%. Not counting the wear on the battery, it's small but adds up over time. It's much better to send that energy down the street to the neighbors house.

BALANCING the grid is another matter entirely. That's not something that can be done ad-hoc but the shill article phrases it somewhat differently.

'The situation, however, is different for utility companies, which could reduce their peak grid demand by up to 32 per cent thanks to solar energy storage and cut down the magnitude of solar power injections to the grid by up to 42 per cent.'

Meaning... distributed storage needs to be coordinated to be effective. If you're using storage only to increase your self-consumption that's probably counter-productive. If there's excess wind available on the grid then you should be importing and charging. If there's a deficit then you should be exporting... even if your battery isn't charged. The larger picture needs to be taken into account.
 
Why not change the title. That is not what the journal article said.

The title is accurate... the entire article is a bit misleading. The title reflects the conclusion.

“I expected that storage would lead to an increase in energy consumption,” said Robert Fares from the Cockrell School of Engineering at the University of Texas at Austin, “but I was surprised that the increase could be so significant - about an eight to 14 per cent increase on average over the year.”

So we shouldn't do that... using storage to only increase self-consumption DOES increase emissions compared to basic grid-tie. This highlights the need for a 'smart grid'. Distributed storage must take the needs of the grid into account to be effective... not just the needs of the household.
 
"The results are relevant for Texas, where the majority of grid electricity comes from fossil fuels"

Renewable Energy Production By State

Renewable sources provide 1.4% of New Mexico's energy production, totaling 33,785 billion BTUs. This is 0.45% of total U.S. renewable energy production.

Renewable sources provide 2.55% of Texas's energy production, totaling 303,697 billion BTUs. This is 4.03% of total U.S. renewable energy production.
 
It appears to me that the study is probably correct and its conclusions vis a vis the effect on total grid emissions likely to be accurate. In Texas, where electricity rates are ridiculously low to begin with, it might not hurt homeowners to export all of their excess PV power to the Grid instead of storing and time-shifting.

Elsewhere, net metering is often laden with punitive conditions, as it is in states such as California where a $10 per month connection fee applies even if your Grid power use is a net negative, or where time-of-use rates are set to $0.35/kWh at prime time late afternoon and evening when your PV is no longer producing. Some utilities credit excess PV power delivered to the Grid at wholesale rates but charge high retail rates for power taken from the Grid. Under such utility company rules, it may be greatly beneficial to homeowners to use storage for time-shifting their own usage even if the total Grid might be harmed. If it is beneficial to the Grid not to store power at home, then the utilities can set their rates in a way to encourage rather than discourage the desired behavior.
 
This is a study of a limited situation which renders it largely meaningless.

Yes, for emissions it's better to send the electricity out to supply demand immediately than to store it. But this is making the assumption that there are just a few solar + storage homes and a lot of fossil-fuel-grid houses.

BUT -- think long term. What happens when everyone has solar panels? Then there will be a surplus of electricity at noon, and it will be better to store it -- and to store it locally -- until a time, such as the evening, when there is a deficit of electicity and to use it then to displace fossil fuel usage.

In short, solar + storage reduces emissions once enough people have solar. This "increases emissions" thing is temporary.
 
  • Like
Reactions: Ampster