Minimising Costs with Ultra-efficient Technologies
The
development of new, ultra efficient technologies is revolutionising the
way that we use energy. The trend towards portable, lightweight,
battery powered mobile devices has finally forced manufacturers to
class efficiency as a high priority.
Any well designed solar & wind energy system uses ultra-efficient
appliances, especially selected for their ultra-low power draw.
Although some of these new devices are potentially expensive, the
financial savings on the cost of the solar & wind power system
often amount to many times more than the extra investment cost.
Passive Solar Buildings
It didn't take long for early cave dwellers to figure
out the advantages of a cave entrance that faced the sun. They also
used the earth as an insulating medium.
Ironically, today we have a world full of highly trained & highly
paid architects, many of whom don't seemed to have learned from the
experience of our ancestors.
The natural energy aspects of a building are called 'passive solar'
properties. Passive solar design makes a massive difference to the
power consumption and environmental impact of any building.
If you want to learn about passive solar design, an excellent example
is the Rocky Mountain Institute (RMI) building. When you read about it,
remember that this building is now over 20 years old.
Water Heating
Most
solar & wind powered buildings use solar water heating panels in
the summer months to help provide hot water. It is rarely viable to
heat water from solar electric (pv) panels.
It is sometimes possible to use spare capacity on larger wind turbines
to 'dump' excess energy into a hot water tank. Interesting results have
been had with compost water heating systems and on a larger scale
anaerobic digestion collects naturally occuring methane.
In mid-winter, water can be heated by gas or a modern solid fuel
burner, such as a high efficiency pellet/wood chip boiler which are
increasingly popular in Scandinavian countries.
DC & AC Systems
Energy is stored in the batteries of a stand-alone system as DC power.
In order to convert it to mains or AC power, like you find from a
normal wall socket - it needs to run through an inverter.
Inverters are a great solution for running occasional AC loads, however
due to their own internal power losses, we do not recommend that they
are used for devices which have longer running times.
Take lighting for example - it can be used 24hrs per day, and so to
have a large inverter sitting on standby, just in case, will use lots
of precious power. The same is also true for audio and refrigeration
equipment.
In most solar & wind power systems 12v or 24v DC lighting is used,
unless the building or cable distances are particularly large.
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