Use of summer energy possible?

[Willy]

This winter I have been using the house of friends in Spain. They have an underfloor water based heating system using solar roof panels and an air-to-water heat pump as the two heat sources. On sunny days the roof panels give a very significant contribution even in mid-winter and of course this will increase more and more as we get closer to summer.

Problem is, the weather gets warmer as well and soon there will be no need for house heating anymore. Then through many months of summer an enormous amount of free energy is wasted. We could apply a small portion to domestic hot water but very little is used during summer - cold showers are fine! Also there is no pool to heat.

My question is, are there any viable solutions available (or being invented that can convert all this energy to another usable form in summer? For example, it would be very interesting if it was possible to generate 230 V electricity to run some appliances or even connect to the house's wiring (via some regulating system, of course).

Surely somebody must be thinking along these lines?

Willy
- near Alicante, Spain

[Mike90250]

500 gallon storage pond for hot water? I've seen a concrete septic tank used, buried and insulated.

[russ]

The basic problem is that you are talking low grade heat (maybe 50 to 70 deg C) and not much of it (maybe each panel produces 200 or 300 liters per day)

Not enough total heat to do anything with.

[Willy]

The basic problem is that you are talking low grade heat (maybe 50 to 70 deg C) and not much of it (maybe each panel produces 200 or 300 liters per day)

Not enough total heat to do anything with.

Thanks, Russ. This seems a bit counter-intuitive though, which of course doesn't mean you're wrong.

Even on short winter days there is already enough energy to heat a house, which is not an enormous task but also not insignificant and definitely useful.

One would think then that on longer and much hotter summer days there definitely would be enough energy for something useful as well. Maybe the problem is that there are no good solutions yet to make use of it.

Willy

[Sunking]

One would think then that on longer and much hotter summer days there definitely would be enough energy for something useful as well. Maybe the problem is that there are no good solutions yet to make use of it.

Try searching for Stirling Engines. About a 200 year old technology.

[russ]

@Sunking - Useful ways that you can buy off the shelf. Today there are not any.

Maybe the upcoming power project will prove the Stirling commercially but not everyone can afford or has a place for a 25kW generator.

[Sunking]

@Sunking - Useful ways that you can buy off the shelf. Today there are not any.

Maybe the upcoming power project will prove the Stirling commercially but not everyone can afford or has a place for a 25kW generator.

Today you can buy a Stirling Low Temperature Differential Engines (aka Low Delta 1 Atmospheric Pressure) off the shelf for low as $89 for a 1 watt unit. The question is why would you do that?

[russ]

Hey! Your are the one proposing the Stirling engine - İ am only pointing out it is not available yet (proven and usefull).

[Sunking]

Hey! Your are the one proposing the Stirling engine - İ am only pointing out it is not available yet (proven and usefull).

I agree that was my point. The technology has been around 200 years and no use for it. That is the problem with Low Temperature Differential or Low Delta systems is very low energy density and conversion. Who in their right mind would pay $20 to $100 per watt?

The only useful way of using the Sterling concept is using parabolic reflectors to generate steam to turn a turbine which is very environmentally unfriendly and extraordinarily expensive for very limited output. The economics just do not work.

[Mike90250]

[QUOTE=Sunking;7531] ....The only useful way of using the Sterling concept is using parabolic reflectors to generate steam to turn a turbine which is very environmentally unfriendly ....QUOTE]

Hey - I use the carbon neutral steam to clear the snow off my sidewalk, and cook my lobster.

Ok, why is free steam environmentally unfriendly ? Heck you can take processed sewage, steam distill it, spin the Sterling , and then get drinking water from the condensate, that's 3 jobs in 1 minute, and no carbon.

[Sunking]

Hey - I use the carbon neutral steam to clear the snow off my sidewalk, and cook my lobster.

Snow in southern California How is that global Warming thing working out for you?