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Student 07 · 03-30-12, 08:06 PM

Hi,
I was reading an article and found it interesting. I would like to hear some different views.

http://www.greenbuildingadvisor.com/blogs/dept/musings/solar-thermal-dead

The article compares Solar Thermal and using Photovoltaics to operate a heat pump.

There are some drawbacks to a solar thermal system: possibility of leaks, cost of pumps & plumbing, storage of heated water, (for some people) Glycol anti freeze maintenance, (for some people) weight of system, stagnation in summer, low output in winter.

The price of PV's has come down significantly, so combining them with a very efficient heat pump is now very competitive. PV's dont leak, they are lightweight (comparatively) and need very little maintanence (cleaning). PV's can't store heat like a solar thermal system; however, excess energy can be sold to the local utility. Excess energy isn't diverted to a heat dump, it is sold. PV's don't have a problem with stagnation. PV's generally perform better under cloudy conditions. PVs can be mouted on a tracker to get even more energy. I am sure there are other benefits of a PV array over a solar thermal array.

The only drawback I can see is that there is no storage of energy (which I think is renewable energy's achilles heel)

In my opinion PVs combined with a very efficient heat pump could produce more hot water, for more months, than a solar thermal system. Without all the maintenance. I suspect that as the price for efficient heat pumps and PVs come down, this will become even better from a financial stand point.

Does anybody have experience from comparing the two systems?

03-30-12, 08:06 PM	#1
Student 07 Helper EcoRenovator Join Date: Dec 2011 Location: Gresham OR Posts: 35 Thanks: 0 Thanked 3 Times in 3 Posts	Solar Thermal is Dead? Hi, I was reading an article and found it interesting. I would like to hear some different views. http://www.greenbuildingadvisor.com/blogs/dept/musings/solar-thermal-dead The article compares Solar Thermal and using Photovoltaics to operate a heat pump. There are some drawbacks to a solar thermal system: possibility of leaks, cost of pumps & plumbing, storage of heated water, (for some people) Glycol anti freeze maintenance, (for some people) weight of system, stagnation in summer, low output in winter. The price of PV's has come down significantly, so combining them with a very efficient heat pump is now very competitive. PV's dont leak, they are lightweight (comparatively) and need very little maintanence (cleaning). PV's can't store heat like a solar thermal system; however, excess energy can be sold to the local utility. Excess energy isn't diverted to a heat dump, it is sold. PV's don't have a problem with stagnation. PV's generally perform better under cloudy conditions. PVs can be mouted on a tracker to get even more energy. I am sure there are other benefits of a PV array over a solar thermal array. The only drawback I can see is that there is no storage of energy (which I think is renewable energy's achilles heel) In my opinion PVs combined with a very efficient heat pump could produce more hot water, for more months, than a solar thermal system. Without all the maintenance. I suspect that as the price for efficient heat pumps and PVs come down, this will become even better from a financial stand point. Does anybody have experience from comparing the two systems?