Since today is the longest day of the year, it’s appropriate to talk about solar energy. In the seventies, we (at Tri Energy Tech) designed and manufactured solar collectors and alternate energy products. We also consulted on solar design and radiant heating systems. Since then, I’ve tried to keep abreast of the changes in technology, materials and techniques as best I could. It appears to me that the most significant changes in order of significance have been the following:
- Decrease in cost of photovoltaic (solar electric) systems
- Micro-Inverters (built in to PV Panels)
- Improved insulation materials and techniques
- Geothermal systems.
- Increased efficiency of photovoltaic systems
In this field, as in many others, it appears that the basics remain fairly constant. When we approached a project the first order of business was always evaluating the microclimate and proper siting. Once the proper orientation of the home was established, then a study in passive solar design was carried out to achieve maximum gain when required for heating and to eliminate any unwanted solar gain and reduce the cooling load. This establishes a sketch of the building shell and then the construction details would be refined with an eye to maximizing the insulation value of the building envelope. By the time you arrived at the design of the heating supply system and supplemental solar/alternate energy systems the requirements were minimized. At the end of the day the home’s energy footprint was minimal and the bulk of the work was achieved from implementing basic good design practices. So when I look at the major differences from 1978 to today, I can see that the basic practices and technologies remained the same. Geothermal systems have improved in efficiency and have great potential, if the price comes down to a point where it can garner wide scale acceptance. The big news still appears to be in photovoltaics and if the price continues to drop (due to increasing production capacity), it may not be long before we are all feeding power back into the grid. The best way to save energy today is still to design and conserve first, which support my old addage, ” it isn’t what you’ve got, but how little you need”.