ᐅ Should You Install a Photovoltaic Battery Storage System or Not?
Created on: 2 Dec 2020 17:42
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Heidi1965
Our new build is already quite advanced. Next week, 15 photovoltaic modules with a total output of 5.1 kWp will be installed. We are getting a heat pump with a capacity of 5.12 kWh. Initially, a battery storage system was not planned because we wanted to live in the house for at least one year to monitor our electricity consumption patterns, and then potentially add a battery or expand the photovoltaic system later. Now there is a new program that offers a 40% subsidy for battery storage—but only in connection with new builds. That sounds tempting. Should we go for it? What capacity should the battery have at a minimum? The condition is: "The ratio of system output to usable battery storage capacity must be at least 1.2 kWp to kWh of battery storage. Storage capacity exceeding this ratio is not eligible for funding." Have I understood correctly that only a battery with a capacity of 4.25 kWh would be eligible for funding?
Or is this all too small? Just “play equipment”?
Or is this all too small? Just “play equipment”?
No, these are all net values, meaning usable capacity. There are 10.2 kWh usable.
It’s December, so it’s dark not only at night. The sun sets shortly after 4 p.m. and doesn’t rise again until late in the morning. This includes household electricity use, such as cooking dinner, baking bread rolls in the oven, watching TV, or any other typical evening activities. But yes, the heat pump also consumes quite a bit. I’ve set a hot water cutoff from 10 p.m. to 10 a.m., but the heating often runs at night as well when temperatures are below freezing.
It’s December, so it’s dark not only at night. The sun sets shortly after 4 p.m. and doesn’t rise again until late in the morning. This includes household electricity use, such as cooking dinner, baking bread rolls in the oven, watching TV, or any other typical evening activities. But yes, the heat pump also consumes quite a bit. I’ve set a hot water cutoff from 10 p.m. to 10 a.m., but the heating often runs at night as well when temperatures are below freezing.
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Heidi196515 Dec 2020 13:13Fuchur schrieb:
Hot water cut-off set from 10:00 PM to 10:00 AMUntil 10:00 AM? But are there still some remnants left, or can you only shower with cold water before that?What should happen to all the hot water overnight? People shower in the morning, and afterwards it might be cold. So far, no one has complained about cold showers.
The reason for 10 a.m. is simply that there is no sunlight before that anyway, so I could just as well do without the restriction. And since both of us are working or the children are at school, it doesn’t really matter whether hot water is available at 9 a.m. or 11 a.m.
The reason for 10 a.m. is simply that there is no sunlight before that anyway, so I could just as well do without the restriction. And since both of us are working or the children are at school, it doesn’t really matter whether hot water is available at 9 a.m. or 11 a.m.
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Pipapelikan17 Dec 2020 12:24Olli-Ka schrieb:
Hello,
so about 600 € (approximately $660) savings per year, around 6000 € (about $6600) over 10 years.
So what does the storage system cost in return?
Is it worth it?
Olli My calculations so far have always shown that an electricity storage system is currently not really cost-effective.
There are too many factors that must be favorable for the storage system to pay off; in reality, you are more likely to incur losses.
Furthermore, electric vehicles will become more common on the roads in the coming years. I’m confident that this billion-dollar market will drive the development of new, cheaper, and more efficient battery systems, which will be used not only in cars but also in homes.
That’s why I would definitely recommend waiting for now.
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WilderSueden17 Dec 2020 12:35Car and home energy storage systems are only loosely related. In fact, their requirements differ significantly in terms of weight, fast charging capability, maximum power output, and continuous power rating. For example, a 100kW (135hp) motor draws very different currents compared to a household. This leads to different optimal battery chemistries. Currently, the use of lithium-ion batteries in homes is more of a makeshift solution due to the limited availability of mature alternatives. If home batteries become cheaper, it will likely be because they are developed differently from automotive batteries, not because car batteries are produced at a lower cost.
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Pipapelikan17 Dec 2020 13:18Sure, that’s true, but according to online sources, the average cost for electric vehicle batteries was
At these prices, I would also install an inefficient battery for the house since it is still many times cheaper. And as you yourself wrote, currently there are few market-ready alternatives. This will certainly change in the coming years, and a battery available now is hardly profitable enough to justify installation at this time. (Exceptions prove the rule)
According to a chart from the news site, the average price per kWh was still 1,160 US dollars (currently 1,040 euros) in 2010. Last year, in 2018, it was only 176 dollars or just under 160 euros.
At these prices, I would also install an inefficient battery for the house since it is still many times cheaper. And as you yourself wrote, currently there are few market-ready alternatives. This will certainly change in the coming years, and a battery available now is hardly profitable enough to justify installation at this time. (Exceptions prove the rule)