On-grid domestic battery storage

pinnks

I'm intrigued about the "hot" water through the boiler issue. What are the given reasons and how hot is hot in this context? I am not in the position of particularly needing to care, just intrigued. For instance, my dishwasher (Neff) expects a cold feed but it also states that it is happy to be connected to a warm feed, subject, I think, to certain upper temp limits. What makes a boiler different?

ASavvyBuyer

pinnks wrote: »

I'm intrigued about the "hot" water through the boiler issue. What are the given reasons and how hot is hot in this context? I am not in the position of particularly needing to care, just intrigued. For instance, my dishwasher (Neff) expects a cold feed but it also states that it is happy to be connected to a warm feed, subject, I think, to certain upper temp limits. What makes a boiler different?

From what I read, some combi boilers have a plastic connector for the cold feed that can't take hot water that is too hot. If it is a metal connector for the cold feed, it should be OK.

However, the boiler needs to "modulate" (I think that is what it is called) the amount of gas heating the water, otherwise it can try to overheat already hot water.

pinnks

Interesting. If your water is that hot it begs the question of why you would put it through the boiler anyway. Indeed if it is over about 30 degrees I would have thought you would just use it and not try to further heat it.

ASavvyBuyer

pinnks wrote: »

Interesting. If your water is that hot it begs the question of why you would put it through the boiler anyway. Indeed if it is over about 30 degrees I would have thought you would just use it and not try to further heat it.

I understand that if water is stored at over 20 degrees, but less than 60 degrees, you need to be wary of legionella.

http://www.hse.gov.uk/healthservices/legionella.htm

Reed_Richards

ASavvyBuyer wrote: »

I understand that if water is stored at over 20 degrees, but less than 60 degrees, you need to be wary of legionella.

http://www.hse.gov.uk/healthservices/legionella.htm

But if it is a thermal store rather than a hot water tank then that should not be an issue.

pile-o-stone

If you fit a mixer valve that blends cold mains water with warm water in the thermal store, then the feed into the boiler can be set to a constant temperature.

We have a mixer valve on the return feed from our thermal store to the boiler. It's set at 55C, which is apparently the perfect return temperature for condensing boiler efficiency. The mixer valve takes water from the middle and bottom of our tank and mixes them together.

On the legionella front, our hot water comes from a mains feed that goes through a heat exchange plate and another mixer valve. This means that the water we shower in is not held in the tank, and the water can never get hot enough to scald us, even if the solar heats the tank to 80C (which is does on sunny days).

markin

This channel may or may not be an interest to some of you, data heavy, but it is in California.

6 power wall 2, 7.3kwh peak Solar, And a Tesla 90D

https://www.youtube.com/watch?v=dWYVKjDuiys

Zarch

I'll admit i'm not anyway near up to speed on EV at the moment.

But reading about V2G EVs and batteries..... i'm hard pushed to think why i'd want to currently throw £2k at 4kwh of static conventional batteries for my solar install when I could put that money towards an EV and the benefits of both the battery and the driving side?

:question:

Reed_Richards

If you drive to work in an electric car and have solar PVs at home then you would have to work the night shift so your car can charge-up at home whilst the sun is shining. In this ideal world the battery in your electric car could also supply power to the house when the car is plugged-in at home.

Zarch

Reed_Richards wrote: »

If you drive to work in an electric car and have solar PVs at home then you would have to work the night shift so your car can charge-up at home whilst the sun is shining. In this ideal world the battery in your electric car could also supply power to the house when the car is plugged-in at home.

You're right.

Apologies, selfishly thinking here as it would be the wife's car ans she only works part time and makes short journeys....... so plenty of opportunity to have it charging in the day via PV.