Do-it-yourself solar thermal projects can make us more energy independent. The greenhouse effect is a miracle of nature that makes trapping heat possible.  Without  this method of trapping heat  our tiny planet would be a frozen waste land like the Moon.  A conscious effort to make better use of this miracle of nature can free us from dependence on non renewable resources and allow us to at last live in a sustainable economy unfettered by the restraints of big business and big government. The greenhouse effect is something that all domestic solar thermal systems have in common....

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Solar collectors also use the greenhouse effect  to capture the sun's energy. Both solar collectors and solar greenhouses are able to harvest the suns energy in the form of heat. Two of these serpentine collectors cover a surface area 60 square feet.
The glazing is more durable than glass and much lighter.
See what people are saying about my Do it yourself book: "How to Build a Solar Hot Water System" 

Solar Panels  are very much different than solar collectors. They use selective wavelengths of light to produce electricity and they work best in  direct sunlight at a low temperature.  Large PV systems are still quite costly. They use inverters to convert DC panel power to compatible AC power. This AC power is often interfaced with the grid so that solar energy may be shared with others. 

Solar Charge Controllers are used maintain an adequate charge on batteries. 
Solar Heat Controllers are used to collect, store and distribute solar heat.

The cost of PV systems has come way down in the last 5 years. With the advent of thin film technology it appears the price of PV will continue to plummet in the coming years, but the question is can we afford to wait much. Every day that we wait is a day that we miss out on a direct connection with the sun.

Heat and power are different animals and we need them both..

The AC/DC Differential Controller  responds to the difference in temperature between collector and storage and turns an AC or DC pump on and off to maximize the heat harvest from a solar hot water or solar heating system.  Temperature monitors are used to display the actual temperatures inside the collector and inside the heat storage tank, but the controller will function without them.  

This AC/DC controller consumes less than 1 watt of power per hour yet it is capable of regulating 300 Watt pumps.  It's a rugged, dependable, analog controller that may be mounted on a wall. The temperature probes and power connections are attached to the terminals on the bottom of the controller to facilitate wiring.

Universal Differential Controller

• An integrated differential on and differential off pump adjustment
  A pump on indicator lamp
  A heat available indicator lamp
  A relay that can handle AC or DC pumps requiring over 300 watts of power
  A voltage regulator that limits current in the probes
  A mounting block
  Two NTC 10K thermistor probes
  Polarity protection incase the DC supply is reversed
  Rugged, easy to use connectors
  Full hook up and diagnostic instructions
  email support