Random Renewables Thread

Has anyone ever heard of something like an MHRV that can recover heat as hot water?

I remember a while back that I read an article about a hot water cylinder with a built in ASHP. The idea was it used warm air in the attic to heat the water

The article was from California and I'm guessing it works better there given the states highly enthusiastic attitude towards summer

Saw another one in the UK which looked similar but used outdoor air ducts and was targeted towards apartments

But it would be pretty cool if you could scavenge the heat given off by some household appliances a bit better.

Cookers, ovens, dryers all give off waste heat, plus any electronics. Not to mention those newfangled hybrid inverter and battery systems that some people are getting 😁

I guess the idea with an MHRV is that it evenly distributes the waste heat around the house so it's put to better use. But that's not always the best idea if the house is already warm

So it'd be pretty cool if one could use the warm air in the house to heat water instead, which could be stored for later use

The mixergy tank is impressive (dunno about prices) and the way it can offer "volumetric heating" mmmm a new buzz word 😉

https://www.mixergy.co.uk/products/mixergy-tank/

Our kids kids will be wondering why we were heating all that water but only using a fraction of it....

I wonder has there been much movement on biogas production in the past year

I wouldn't call it a long term solution but digesters are pretty easy to build and scale up, and we already have a lot of cattle (not to mention other sources of methane) so it seems like a no brainer

AFAIK biogas generally gets held back when natural gas is cheap because it's more expensive to produce. But with natural gas prices through the roof and about to reach high orbit then alternative fuels should be much more competitive

18c per kwh is nice but if the idiots in charge don't cap the "standing charges" I can see that loophole being used to continue to gouge customers.

Are these tiles a pain to mount panels on? I'd be able to access the back of it easy enough to go through the felt

Got the virus, classic 😂

Seriously, there must be some kind of obsession with people and electrification. Literally everyone I know who has bought an EV has either gotten or is considering solar panels and looking at way to move away from fossil fuels

I mean it makes complete sense, I'm sure if you could put panels on your house that magically made petrol then everyone would have them.

And having moved to EVs myself, I don't want to see anything with a petrol engine on it anymore. I even got annoyed a few years back when I rented a compactor and had to get a petrol one because the electric one wasn't powerful enough. So it's electrification all the way as far as I'm concerned

I just find it very funny how everyone seems to get thinking along the same path.

Either it's get an EV, then solar and maybe heat pump

Or get solar, then EV, then heat pump

It's up to you but personally that's one bit I'd pay the professionals to do.

If I was doing it myself then at some point I'll be standing on the roof holding a big heavy panel and trying not to get blown off

I wouldn't want to find out the hard way that I'm actually quite bad at it

I hear ya, I was just replying the earlier post about what is involved. And the safety aspect of being up on a roof is indeed a large factor in me having gotten an installer in, so far.

@SD_DRACULA - same here. Didn't need to do any cutting myself, I have the brackets coming out from under the arch of the pantile if that makes sense.

You guys are in the ha'penny place with you're roofs. I've got a field to expand into 😂😂

Speaking of jealous of spare land for solar. @SouthWesterly (and I'm jealous of your field too)... this lake is using well under 1% of space to get 12,000 floating panels. Reduces 1) heat on panels so better performance in summer 2) reduces water evaporation. Ignoring the 30% dearer to install, lakes / reservoirs are space every country has that they likely don't need to buy or lease. And they say later that land gets expensive closer to large population centres (where you need the large solar farms). So using water bodies could help as there needs to be loads of water in those places.

Edit: fixed link Floating Solar Farms Are a Game Changer (reasonstobecheerful.world)

I've seen other places trialling it in likes of Middle East over narrow irrigation canals. Primarily to reduce evaporation as they lose heaps in that temp

Your link doesn't work, but here it is fixed:

You'd presumably get the CEP with that size of an installation, which is a bit lower. I imagine with the amount you'd be generating it's still worthwhile despite the lower rate

Stopping them getting nicked will be a whole spin off industry. Will need some way they are all fairly well locked in place :)

I have done some digging on using a piece of land, I think it applies to lots of shed roofs too. Essentially, the impression I got after some conversations and research is you need to be self consuming a chunk of it, or have a local energy thirsty business (e.g a factor) to use a large chunk of it. This means you can do a deal with said factory to guarantee a certain price over a long period. On a larger setup with cost of ground mounts especially, I suspect the business plan will be based on 10-15 year revenues? There is no guarantee FIT will be useful in 5-6 years, hence the benefit of a heavy user in close proximity. (this relates to a smaller piece of land, a much larger piece will obviously overcome the initial fixed costs like connections, sub-stations, etc far easier)

Spain pumped money into incentivising solar panels years ago, including FIT, the big boys flocked in and saturated spain with solar, so bonus pulled - 62,000 people now bankrupt (and many no doubt suffering with mental health due to stress/protests)

https://www.france24.com/en/tv-shows/focus/20220221-spain-s-solar-energy-crisis-62-000-people-bankrupt-after-investing-in-solar-panels

https://www.youtube.com/watch?v=-0gbisTsj2w