Solar energy at home.

[Mr. Widget]

PS There is one major drawback to roof-mount PV panels, at least where we live...

Living in California and not up in the mountains we don't have such dynamic conditions and so I haven't researched this, but wouldn't a low wattage heating coil under each panel be a practical solution?

 

[Osvaldo de Garay]

If you can ensure good thermal conduction, you'll get twice the benefits: cells will work cooler, and as all semiconductor, it's good for them, and also you'll get warm water. The point is where the complicated of the task, is exeeded by the advantages.

 

[mhardy6647]

Living in California and not up in the mountains we don't have such dynamic conditions and so I haven't researched this, but wouldn't a low wattage heating coil under each panel be a practical solution?

I don't know, but it's certainly not common. I know of no such systems around here (and lots of folks around here have PV arrays).

The other two panels on the far left of the back roof are heat exchange panels for domestic hot water solar preheat. On a day like this, the water (actually a water/glycol mixture; which heats potable water indirectly in a tank in the basement) going through them heats to about 140 degrees F (60 C). I am not sure how much value they really add for us, but my wife wanted this (her parents had 'em on their retirement home, installed in the 1970s!), so we had that installed, too, when the house was built.

 

[Osvaldo de Garay]

60 Celsius? Good. Has it some means to regulate or adjust this temp?

 

[ianovic69]

A heat pump does not generate electricity. It generates efficient heat or cooling, depending on how it's configured.

Electricity can be generated via a geothermal power plant. A bit of pipe under your lawn won't cut it. You'll need to be very deep to get to much higher temperatures for this. This isn't exactly consumer level technology

Thanks for this, I hadn't fully understood the principles.
Looks like it's either add solar or carry on as we are.
I'll look into solar but I'm not convinced it will make enough difference to warrant the cost. If it seems like it will I'll come back here for further discussion.
Who knew an audio website forum would be such a great place for sensible informed information on renewable energy?
Amazing stuff!

 

[voodooless]

Who knew an audio website forum would be such a great place for sensible informed information on renewable energy?

An audio SCIENCE website I think that is the biggest discriminator here. Generally it’s the type of people that are interested in multiple technical fields.

I'll look into solar but I'm not convinced it will make enough difference to warrant the cost

Over the last one-and-a-half-years went from gas powered heating to heat pump, solar and batteries (and a fair bit more insulation). My monthly energy costs are now about a third of what I paid before. Obviously this will not be the case in all environments

 

[Salt]

I am having this dilemma from some months now, and I never thought ASR could be a place to ask.... but everywhere else I asked, the answers become fast political and are of little help.

Ok, the economic side:
I live in Luxemburg and even though my roof has a pretty good orientation and the government helps with the initial investment, the climate and the incredibly high installation prices vs neighbor countries make that we would need 7-10 years to break even, and at that point we might have to start thinking on replacing the battery (? not sure what is the state of the art). All in all it seems a pretty bad investment on my book.

People tend to counter this saying that the panels allowed them to have the AC running full power all summer, but we are more windows wide open kind of people, I wouldn't want air conditioning even for free.

On the environmental side things get much more complex, and this is the part I struggle more having a meaningful conversation with anyone, as people tend to rely on very simplistic arguments.
Filling the house with hundreds of kg of electronics, batteries and structural elements that for sure carry a heavy footprint to have them working well below their possibilities in central Europe doesn't seem like a no brainier to me unless someone shows me the numbers. And most especially when a good chunk of the electricity we buy today is from renewable sources. I know there are a lot of caveats here,and that my money will also help suppliers to keep advancing the technology, but my point is that I don't have enough information to make an informed decision.

Another argument to postpone the investment is the expectation that the technology evolves further, especially on the battery side. Also reverse charging (or whatever it is called) using a car battery sounds attractive, but is not available where we live at the moment.
Would love to hear your opinions and would love to be proven wrong. Thanks!

Did you ask for 'break even' for your 'Investement' when you installed the gas/oil/whatever heating? No? Right, it was a necessity, otherwise it could be very cold in winter.
Why is it now an 'Investment', as it was never before?

 

[Timcognito]

I am having this dilemma from some months now, and I never thought ASR could be a place to ask.... but everywhere else I asked, the answers become fast political and are of little help.

Ok, the economic side:
I live in Luxemburg and even though my roof has a pretty good orientation and the government helps with the initial investment, the climate and the incredibly high installation prices vs neighbor countries make that we would need 7-10 years to break even, and at that point we might have to start thinking on replacing the battery (? not sure what is the state of the art). All in all it seems a pretty bad investment on my book.

People tend to counter this saying that the panels allowed them to have the AC running full power all summer, but we are more windows wide open kind of people, I wouldn't want air conditioning even for free.

On the environmental side things get much more complex, and this is the part I struggle more having a meaningful conversation with anyone, as people tend to rely on very simplistic arguments.
Filling the house with hundreds of kg of electronics, batteries and structural elements that for sure carry a heavy footprint to have them working well below their possibilities in central Europe doesn't seem like a no brainier to me unless someone shows me the numbers. And most especially when a good chunk of the electricity we buy today is from renewable sources. I know there are a lot of caveats here,and that my money will also help suppliers to keep advancing the technology, but my point is that I don't have enough information to make an informed decision.

Another argument to postpone the investment is the expectation that the technology evolves further, especially on the battery side. Also reverse charging (or whatever it is called) using a car battery sounds attractive, but is not available where we live at the moment.
Would love to hear your opinions and would love to be proven wrong. Thanks!

This is a US company that acts like a go between to help people with their energy purchases so they can not help you directly, but the site is filled with basic and quantitative data on pros and cons of solar, backup systems, heat pumps, EVs and EV charging.

Compare and save on clean home energy solutions

EnergySage is the simplest way to shop for clean home energy solutions. Join over 50,000 homeowners who have electrified their homes with EnergySage.

www.energysage.com

 

[Salt]

An audio SCIENCE website I think that is the biggest discriminator here. Generally it’s the type of people that are interested in multiple technical fields.


Over the last one-and-a-half-years went from gas powered heating to heat pump, solar and batteries (and a fair bit more insulation). My monthly energy costs are now about a third of what I paid before. Obviously this will not be the case in all environments

Same here and satisfied (esp. in sight of what happened in near east)

 

[mhardy6647]

60 Celsius? Good. Has it some means to regulate or adjust this temp?

I honestly have virtually no idea of how it works. Yes, it must, and I know it has a blow-out valve up on the roof.
I do know it has a circulator pump that turns on when the temperature on the roof gets high enough to make circulating the warm water worthwhile. I imagine if it gets too hot, it would shut off, and possibly vent... I presume it's designed not to get too hot.

The hardware is from a company called Stiebel Eltron, who it appears are still making such gadgets. I guess they've been around for a while.

 

[mhardy6647]

An audio SCIENCE website I think that is the biggest discriminator here. Generally it’s the type of people that are interested in multiple technical fields.

I have long told folks I am interested in pretty much everything that there is (to be interested in*) except for boats and guns.
Nothing moral or ethical just never had much interest in either of those classes of things.

_____________
* I just added this qualifier, since some things that there are to be interested in aren't -- at least not yet.

 

[Salt]

I honestly have virtually no idea of how it works. Yes, it must, and I know it has a blow-out valve up on the roof.
I do know it has a circulator pump that turns on when the temperature on the roof gets high enough to make circulating the warm water worthwhile. I imagine if it gets too hot, it would shut off, and possibly vent... I presume it's designed not to get too hot.

The hardware is from a company called Stiebel Eltron, who it appears are still making such gadgets. I guess they've been around for a while.

You can define a maximum boiler temperature (85 ° C in my case) at what the circulation pump stops. Never made it to this temperature though as my boiler is 1700 liter.

 

[Osvaldo de Garay]

My apologies for going off topic in this web site with this post away from the main objective of it. But it went unexpectedly well received in the community. If mods feel it deviates too from the target, close it.

Said this, I didn't find forums were to chat about this thing(s).

Also forums about ham radio are very little where chat seriously and ads free. Last I participated was from an English man John G4HHA (or perhaps G4HAA) who for reasons of health has to abandone and close it.

 

[Salt]

Living in California and not up in the mountains we don't have such dynamic conditions and so I haven't researched this, but wouldn't a low wattage heating coil under each panel be a practical solution?

There are hybrid solar panels on the market that combine a photovoltaic layer on top with solarthermic layer beneath, so that the pv layer is cooled and warm water generated simultaneously.

 

[Osvaldo de Garay]

Interesting convination. I don't see it here still.

 

[Salt]

Some informations on a German site:
https://www.energie-experten.org/erneuerbare-energien/photovoltaik/solarmodule/hybridmodul