Tuesday, June 17, 2008

Renewable Energy and the Web

I am always impressed whenever I go to create the News section of EB just how much innovation is going on out there. Sometimes it really gets me thinking. One of the things that grabbed me this week was the information we came across on Enphase energy which has developed a new type of inverter for solar systems called a micro-inverter. Instead of providing a single inverter for all of the solar panels, it has developed a small micro-inverter which attaches to each solar panel individually. This allows the energy signature of each solar panel to separately managed and monitored. This struck us as a significant advance in solar energy, particularly if they can get the costs down on the product (don't have pricing data on it yet) because it allows the solar system owner to really track what is going on with their system at a discrete level. Solar panels are incredibly reliable components but occasionally they do go out. When this happens it might only show up as a slight drop in voltage on one of the strings depending upon where it is placed in the sequence. A homeowner could easily miss it altogether. By allowing it to be monitored individually it would be easy to notice when an individual panel failure occurs.

Another advantage of this type of system is that it allows the power curve for each panel to be monitored separately. Maximum power point tracking (MPPT) can be used with each panel. This function ensures that there is an optimal balance between volts and amps so that the maximum amount of watts of energy is produced. By doing this analysis at the level of each panel rather than all of them at once each panel can be optimized resulting in better overall performance. It is not yet clear whether or not the improved energy output is more cost effective than a single inverter but as component costs come down it seems likely that this is a better approach to power management.

The part about the Enphase inverter that I like the best is that it is Web connected. You can simply log on to to their Website and look up a page that will show you the output of your panels in real time. This strikes me as way cool! It seems to me this has got to be where things are going to go in renewable energy. It is part of the trend we have seen in making the output of a solar system more visible. For some time now inverters have come with displays that can provide detailed information about how your solar panels are performing. More recently, a few inverter manufacturers have made the display devices wireless so that you can mount the display somewhere convenient rather than down in your basement where the inverter probably is located. Moving the display to the Web was the logical next step.

Logical and potentially quite powerful, not only for the individual, but particularly for communities. One of the real trends in renewable energy in Europe has been the move to communal efforts to establish renewable energy. Many communities in Europe have joined together to buy a commercial windmill or a renewable energy system and then share the generated electricity throughout the community. In essence citizens are taking the future of energy in their community into their own hands, often when their governments are not responsive (something those of us in the U.S. are all to familiar with!). For a great discussion of this approach I highly recommend Greg Pahl's book "The Citizen-Powered Energy Handbook" which you can find in our main book section.

It seems to me that putting energy output on the Web would be a huge boost to citizen powered energy efforts because it makes the result of an energy investment so completely visible. At any time a member of the community could log on to the Web and see what type of output their windmill or solar system is providing. They can see the benefit immediately and tangibly. Compare this to the average state utility. Somehow I can't see Con Edison letting me see the output of the electric generators at their local coal-based electrical plant. Could be interesting though, modern home inverters on renewable energy systems actually tell you how many pounds of polluting carbon you are offsetting by not using energy from the grid. Think Con Ed will tell you how much carbon they are putting in the atmosphere?

Now that we have entered the post-peak oil era people are starting to take their energy use a bit less for granted. Making that use easily visible via the Web will make that even easier. Here's an idea; why don't we pass a law requiring all government buildings to use Web based monitor's for their energy systems and then we can see which agency is wasting the most energy. Could be fun!