Friday, April 12, 2019

Solar Electric And the Brave New World of Battery Systems

2019 is a great year to do a Solar Electric system, also known as Photovoltaics, or "whole house".

  • A lot of companies do just PV, and not hot water.    
  • It may seem surprising, but hot water systems are actually more complicated to do and take more skills and tools.    
  • I say this to clarify that "whole house" solar does NOT mean that you should have just the PV Electric.   
  • In many cases, it makes more financial sense to ALSO have the Solar Hot Water, which can account for about 40% of your bill (mostly depending on if you are a heavy aircon user or not.)
In this brave new world of solar, at least in the Hawaii grids, you can no longer get your bill to near zero unless you are using batteries to supply your nighttime loads.    It is just the way that HECO and the PUC have set up the systems.  

You charge your batteries in the daytime (as well as covering your own electrical demand).   HECO has basically 4 programs available, but the basic data collection will be the same for all.

If you have  the old style dial meter, click HERE, to see how to read the kWH reading on the meter.

If you have the newer NEM style meter, click HERE.

Finally, in order to size your system and batteries, the following information is important IF you want to make the best decisions.

It would be good to collect this data on three normal days (normal daytime and nighttime use), not if you have house guests, etc.