Posted by Tim Stobbs on January 24, 2008
Alright, I normally don’t talk about just pure environment issues, but I’m in a bit of an odd position that I understand some of the challenges facing newer technologies in the market place from a combination of research and various life experiences. So here is a short guide to alternative sources and their issues. Please note some of my information might be a little out of date with very recent changes, so if I’m incorrect on anything please provide a reference link in the comments and I’ll update this.
Solar – Photo Electric (PE)
Pros – Once installed they can last for a very long time (25 years +) and produce power from the sun with no additional green house emissions beyond their initial production. They can fitted anywhere which makes them idea for remote locations.
Cons- Low efficiency (30% is the max it can do while the sun is shining so overall is a lot less). Produces DC power only during the day, so an inverter is required to get it to the normal house hold AC power and power storage is required to use it at the night time (ie: batteries). The other way to have power storage is if your area allows net metering and you sign a power generation contract with your local provider. Then your excess energy in the day will go out to the grid and offset some of your power usage at night. So you require backup power generation on another fuel to keep the overall grid stable. Solar projects typically have pay back periods of 20 years or more (ie: they are not cheap).
Solar – Heating (Active Hot Water)
Pros – Depending on system design it can provide household hot water and/or space heating. Considerably more efficiency than solar PE and cheaper to install (pay back period can be under 10 years). Depending on location it can provide up to half a family’s hot water requirements (or more for the southern States).
Cons – In freezing climates a glycol loop is required to prevent freezing. The system depending on the day only preheats the water so a traditional or instant hot water heater are required to boost temperature and act as backup. If used for spacing heating additional piping and distribution is required (either hot water in floor heating and or radiators). Also a space heating backup is required.
Wind – Electrical Power
Pros – Similar Pros to Solar PE – See above. They require more maintenance than solar PE, but depending on location can reach 40% efficiency.
Cons- The wind doesn’t always blow, so back up generation is required. Also high speeds (for example over 90km/hr) requires them to shut down to avoid causing damage to themselves. Ideal conditions require a large open area, so they don’t work well in most inner city applications. With high global demand prices are not cheap.
I’ll pick up this again later and look at clean coal, tidal and nuclear power generation.