Living And Working In Sustainable Environments – Load Balancing

An important part of reducing cost as well as saving resources will be the technique known as Load Balancing. Often municipalities get offered energy at night for free or even being paid to take a certain amount of energy at low usage times.

This is mainly due to the efficiencies of turbines at a certain production rate. This means that if you can take and store that energy at times of overproduction and use it at times of high demand instead of taking power from the grid, significant savings for energy providers and consumers can be achieved.

The only practical storage technology today are batteries, as conversion into hydrogen gas is currently too expensive a solutions while flywheels can only be used for very short-term storage. If you happen to have a lake of course you can pump water from a lower level to a higher level and drive turbines when you need the extra energy.

Battery technology is not perfect but better than it was 10 years ago and the best candidates are Lead Acid and LiFePO batteries as both are relatively maintenance free with LiFePO having the better charge/discharge efficiency. The cost is lower for Lead Acid technology but the weight and volumetric size is 4 times that of the LiFePO. The cycle-life of industrial Lead Acid batteries with 2000 to 3000 cycles is actually better than the 1500 to 2000 cycles of LiFePO batteries. However, the overall energy efficiency of LiFePO is much better.

Where does load balancing make sense? If you have already paid for your batteries to store energy from solar, wind or bio-mass generation adding load balancing makes great sense as you do not have to amortize all of your battery capacity from the savings of cheaper off-peak power.

There is another way of looking at load balancing that makes extreme sense, at least until energy providers increase their rates drastically, this is short-term load balancing or totally avoiding demand charges. In a way it actually helps energy providers by not having to have capacity on-line just in case you want to peak your energy use. This kind of load-balancing is also known as demand-muffling. Machines may have to be adapted or modified to be able to make use of this technique.

Demand Muffling stores energy in batteries of sufficient size to operate the machine for a full working day. The energy is fed into the system at a constant much lower rate thus balancing the demand over a 24 hour period or longer if the machine is only used sporadically. For ovens that take a lot of power to heat up initially but not so much to keep the temperature this can change the demand charge from the energy provider from several hundred dollars a month to none, allowing a very fast amortization of the investment into machine modification, battery chargers and batteries. Cycling electric ovens, Wave Solder and Re-flow Solder machines are ideal for this kind of conversion.

All the more reasons to believe that 48V-DC Systems or a mixed AC delivery combined with a local 48V-DC System to buffer energy as well as 48V-DC devices directly making use of DC power will enter home, office, factory and server farms over the coming years.

If you are and Architect, Interior Designer, Mechanical or Electrical Engineer get used to the fact that in a transitional period DC and AC systems have to be accommodated in sustainable environments and the planning for them is paramount to keep cost of transition affordable.