30 years ago, everyone hoped that the world would get more and more advanced and more politically stable. Today it looks as there has been a lot of technological advancement but the supply of energy is getting more uncertain.
This is partly because the world dynamics have presented us with a much more destabilized oil supply and governments have an interest in increasing taxes on energy and water not because there is a severe shortage of resources but to feed their ever-increasing spending habits.
One strategy for every small business to consider, when you own your habitat or intend to remain at location for the next 10 plus years, is to get more independent and reduce the dependence on grid delivered energy.
With Solar Panels at rock bottom prices and battery technology ever improving, today’s technology allows to move to operations largely powered by alternative energy that use the grid as a backup. For example a Light Fixture that has 48 Volt DC and 100 to 277 Volt AC grid supply can be connected to both systems, a Battery Backed Up DC system supplied by solar or wind energy, and the grid.
Why 48Volts DC and not any other voltage?
When deciding what the best DC voltage is to use around your home or factory we came to the conclusion that it had to be:
- within the internationally accepted Low Voltage Directive (LVD) and hence below 75 Volt and
- it also wants to be the highest safe voltage so as to reduce cost of copper wiring. When running with half the voltage (24 Volt) the current requirement would double and with it the conductor size, doubling the cost of the wiring infrastructure.
Therefore the most practical and safe voltage is 48 volt nominal which happens to be 60 Volt fully charged without an electrical load and still be below the 75 Volt of the LVD.
There are suggestions in the Server Farm arena to use much higher DC voltages which I recommend against in a small environment, mainly due to their dangerous nature to electricians and users. Their attraction lies in much lower wiring cost, however the safety factor should be given the higher consideration.
What else is essential?
Off-the-shelf affordable and canned Energy Management Systems are an essential part of using alternative energy wisely. They allow optimal management of energy while providing maximum user convenience by using occupancy, temperature and daylight sensors to avoid using energy when it is not required.
Can Air Conditioning run off DC?
Yes it can. There are solid state air conditioning systems that can run straight off a 48V DC source. They often do require a water loop to transport heat in and out of the building and may be more practical on a re-model or new-build rather than a straight retrofit. Those systems also rely on heavily insulated rooms as they typically do not have the overcapacity of conventional air conditioning systems.