The Effect of Batteries on Energy Consumption

Hi Tom,

I think you are out of Armenia?

I believe you are asking about the Grid--As in the utility power distribution, vs the "grid" of support wires/frame inside some battery types such as lead acid?

And when you ask about "tension" on the grid, you are asking about how the utility Voltage (sometimes referred to as "tension") is balanced/controlled on the utilty electrical network when solar+"Grid Tied" or Utility Interactive AC inverters are installed on the roofs of homes/businesses/"solar farms"?

The short answer is that a standard AC generator (technically an Alternator) is a "Voltage Source"... So, within its capabilities, the alternator will regulated the votage on the electrical network... Just like a car battery regulates the voltage in the car's electrical system from ~10.5 to 15.0 volts (dead battery to charging battery).

And, the amount of solar Grid Tied (utility interactive) AC Inverters are "small" compared to the utility network/generation sources.

More or less, when the GT inverter generation capacity is less than 5% to 10% of the network total generation capacity, then GT inverters are a "don't care". They produce so little current/energy (relatively) compared to the utility's generators, that they distributed small amount of GT inverters just do not change the overall utility voltage.

Yes, locally, power normally goes into the home (complicated AC electrical mathematics). And the GT inverters can (and do) generate more power than is used in the home, and flows "backwards" through the utility power meter and even through local transformers. And the excess power is typically consumed by nearby homes and businesses.

Not to say that GT Inverters cannot cause network problems.

• In some states like Hawaii and Nevada (and perhaps others), they have stopped installing any more GT inverters. Mostly because the utilties lose money because folks with GT inverters can pay near zero $$$ for their power, while others have their power rates increased to pay for those subsidies.
• When GT power is over ~5%, it becomes an issue for network engineers to manage the voltage across the whole network... In some regions with high numbers of GT inverter systems, it can raise the local line voltage enough to cause damage to appliances and force the utility to shut down the grid in those areas.
• If there are too many/too large of GT inverter installations, it can make the utility install larger transformers and heavier distribution wiring to mange the higher current/power from those GT installations (or they may refuse GT installations, rather than redesign/new install of networking hardware).
• Some newer GT inverters can take "signals" from the utility and cut back on their power output to the grid (frequency is not 50.0 or 60.0 Hz, but is moved +/- 1 Hz or so away from nominal). So the utility can "make the GT inverters" cut back on their power generation and help keep the network up and running.

-Bill