Passive Solar is the way we build something to let the sunlight in or to block it out. This includes facing a building solar south, using materials with thermal mass in them like stone or tile (which stores heat during the day and then releases it in the evening), building window overhangs and planting deciduous trees to shade the home during the hottest months.

Active Solar, on the other hand, is the act of collecting the sunlight's direct heat and then moving it to another place for use, usually within the building. Photovoltaics and Hydronic floor heating systems that utilize solar collectors are two good examples of active solar.

Photovoltaics is_ the conversion of sunlight into electricity. Photovoltaic cells or solar cells are devices that convert light energy directly into electricity. They are packed together in a sealed weatherproof package called a module. Modules are then wired together into PV arrays, and these arrays are what we all recognize as solar panels. Without getting into too much detail, consumers can choose to use the collected energy directly or store it in batteries. For more information on Photovoltaics, go to ge.ecomagination.com and search photovolataics, or for more local guidance, contact PAREI (Plymouth Area Renewable Energy Initiative) 190 Main Street Plymouth, NH 03264, or go to www.plymouthenergy.org..

Photovoltaic cell, module and arrays

Hydronic floor heating, sometimes called radiant flooring, is a system of tubes that carry a heated liquid through the flooring material. Roof-mounted panels collect the sunlight and heat the liquid which is circulated to a storage tank. The tank is hooked up to a pump, sensors, a back-up heat source, etc. that sends thermostatically controlled heat through the tubes embedded in the floor. This type of heating not only cuts energy costs but is less likely to cause irritation in those with allergies. I have seen some houses with this flooring in the garage, but most install it in the basement or first floor. Check out www.healthyheating.com for more info on radiant heating.

I mentioned PAREI previously. What I understand about PAREI is that they are a group, composed of members, who actually help each other in the installation of these solar collectors as well as being a resource for each other. One such solar collector is called the Apricus.

An Apricus Hot Water collector uses vacuum glass tubes to absorb the heat. Inside the tubes, copper pipes reach high temperatures which heat the water being pumped through the collector. The water is then sent to the hot water tank and further circulated through the house. According to their website, http://www.apricus.com/, ‘Installing just one Apricus solar thermal collector can reduce CO2 levels as much as planting more than 200 trees and is the perfect choice for people wanting to become part of the SOLUTION by reducing their carbon footprint.'

To save even more, consider a tankless water heater.  Chi-ching!