TABLE OF CONTENTS As we discussed in Chapter 4, renewable energy is energy from sources that are free and replenishable. According to the Environmental Protection Agency, about 2% of our power currently comes from renewable sources, the largest of these being the burning of biomasses like wood. In earlier chapters we discussed ways to bring down the overall energy demand of a building. Now that we know what our energy demands are, we look at how we can utilize the renewable resources available to meet need.
There are seven recognized renewable energy sources:
Solar
Wind
Biomass
Hydrogen
Geothermal
Ocean
Hydropower
We can now begin to investigate how to use those seven resources to their fullest potential within our project.
The ability to use the most common renewable energy sources, solar and wind, is directly dependent on climate and place. For example, photovoltaic systems and solar hot-water heaters require access to sunlight. Some areas might not have enough sun exposure to rely on either of these systems as the primary power supply. For example, Albuquerque, New Mexico, receives 6.77 kWh/m 2/day of solar radiation on average, which is a great supply. Chicago, on the other hand, receives only 3.14 kWh/m2/day, less than half of Albuquerque. In either case, the placement of solar energy capturing systems needs to have access to the sun. At the micro-site scale, existing vegetation or taller neighboring buildings might block solar access.
