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Maximizing Solar Savings on Country Properties with Net Billing Tariff (NBT)

Over the past 17 years in addition to designing and selling solar systems, I geeked out thinking of ways I can use power differently to maximize homeowners’ power savings.   Having said that, not many people share this passion (including my wife) and being the energy police may not lead to household harmony.  This blog will focus on how a few simple changes can increase financial benefits with PG&E’s Net Billing Tariff (NBT),  if homeowners in the country are willing to adjust how and when they use power.  Why the focus on “country” properties? Because there are a few big differences between country properties and their urban cousins (we will cover urban homes in another blog).  These differences are in how country homes obtain water and get rid of sewage. Other differences often include the need to irrigate larger landscapes, gentleman vineyards and orchards.  Country homes also often have multiple out buildings, more food storage requirements, and even multiple families living on the same property that requiring larger electrical loads. 

First let us pack our bags with a few concepts before we get into the details.


Country property’s have wells.  One of the biggest users of power on most country homes is drawing water from a well with a well pump.  Typically, well pumps, pump water into a storage tank and then a booster pump, pumps the water from the tank to the home.  With NBT it is always a good idea to use water, when possible, during the day when this “pumping” electricity can be drawn from solar. 


Septic Systems: Many country properties like mine are not connected to sewer systems but have septic systems to get rid of sewage and household water.  While there are many designs, I will focus on two, gravity fed and pumped septic systems.  In gravity fed systems no electricity is needed, the home is higher than the septic system and the affluent from the septic tanks travel downhill to the leach field (allows affluent to absorb into the soil below the surface).  On properties like mine, where the home is below the leach field, I need to pump my affluent to the field.   This is important since if we flush a toilet or take a shower, it could cause the well pump, booster pump and septic pumps to be activated.  One way to minimize affluent to a leach field is to have a grey water system, where non-toilet water is on a separate system and used most often for irrigation.


One note, this blog is dedicated to if we change behaviors in how we use energy differently or at different times during the day.  Primarily, how we can shift power usage from evening use to daytime use when our solar systems are producing power.  The other option is to make no changes or minimal changes to our behaviors and add more storage batteries.  It really gets down to if you can comfortably shift evening usage to daytime usage or add more storage to cover evening electrical loads.


One great service we have in Sonoma County is the Sonoma Clean Power Advanced Energy Center, located in Santa Rosa.  Many of the newer technologies I will be discussing below can be seen, borrowed, or bought at a discount from them.  They also have a list of qualified installers and program’s offer to help finance the costs.


Okay our bag is packed, lets discuss specific ways most homeowners can shift power usage.


Irrigation can be one of the largest individual uses of electricity on a country property.  In the old days under NEM, I often suggested to people to run their irrigation during the evenings, when rates were lower.  Many did not make this change as they worried that if a water line broke in the evenings, it would go unnoticed till morning.  Under NBT it makes sense to irrigate during the day while the solar is producing, allowing the solar to cover the well and booster pumps usage when irrigating.  As mentioned above, a grey water system can extend the life of a septic system but also water from showers, dishwashers, sinks and cloth washers serving a secondary purpose to water plants, without the need to pump it.

Heating your home can be one of the second largest power users on country properties.  In the winter heating your home is usually done one of four ways, using a force air natural gas (NG)/propane heater, base board heating, wood stove or using a heat pump/mini split.  First if you have baseboard heaters, or resistance heaters, and use them frequently, I recommend replacing them with a heat pump/mini split which are up to 4 times more efficient.  In many areas using wood stoves is no longer an option and I have noticed as my customers age,

managing wood become less desirable for many.  Force air furnaces burn gas or propane to heat air while central heat pumps use electricity.  Both forced air furnaces and central heat pump systems use venting to distribute heat through a home.  Forced air systems use some electricity, a blower fan, to quickly heat homes.  Central heat pumps take longer to heat a home but are excellent at holding a set temperature.  A mini-split is a heat pump that is not vented but install in a central location or multiple locations throughout a home (zoned).  I first learned about Mini splits when traveling to Central America and Europe where they have been using them for years. At my house I first installed one in my granny unit to make heating easier when my mother-in-law moved in, as it only had a wood burning stove.  About a year later I added one to supplement my force air heater in our home.  Let me explain how I reduced my gas bill by over 60% with this blended system.  My nest thermostat turns on my forced air unit at 5:45 am and preheats my home.  I then use my mini split through the day when my solar is running to maintain this temperature.  Heat pumps and mini splits work very well with NBT to allow most heating to be done with solar power.


Washing dishes, cloths and bodies are often an easy switch for some.  Change your habits to do laundry, dishes and even take showers during the day can have a significant effect on evening power usage.  Solar will not only cover the loads of dish and clothes washers, but also the water that is required to be drawn from the well, and/or booster pumps. 


Heating your food: While many homes still use propane and NG for their range and ovens, things are changing.  We are now seeing gas ranges with electric ovens and like many, I just install an all-electric induction stove and oven.  While induction stoves are 5-10% more efficient than electric ones they do offer one main benefit.  I have never met anyone who likes to cook on an electric stove, they are slow to heat and often do not distribute heat evenly.   Induction stove both heats immediately like gas and because they create heat in conjunction with the pan or pot distribute this heat evenly.   And yes, being electric they can be used during the day on solar power. 


Cooling your Home:  Central heat pumps and mini splits mentioned above can also be used like air conditioners A/C to cool a home primarily during summer.   These systems are excellent ways to work with NBT since summer is when solar produces the most and cooling air is one of our greatest uses of power in summer.  One thing I always try to do in my home is pre-cool my home using solar power (having good insulation helps here), so I rarely need to run my mini split in the evening.


Electric Cars (EV’s), motorcycles etc. are also an excellent way to minimize exports from solar with NBT.  In the days of NEM, I charged my EV after midnight, when rates were cheaper from

PG&E.  But under NBT, we want to be charging our cars when our solar is running.  For those of us who are retired, or who work from home, this is much easier to set our cars to charge any time after 9:00 am for example.  But even if you work a 9-5, you can still charge during the day on weekends and holidays.


Hot Tubs:  While I don’t do this, I do have a few customers who under NEM installed timers on their hot tubs so they would not run during peak power timeframes.  No reason this concept could not be modified to only power hot tubs by solar during the day, so it will be ready when your work is done.


Pool Pumps: This is another great opportunity for NBT.  When customers had pools under NEM, I often recommended that they run the pumps (often 6-12 hours) during the evening to save money.  Many could not do this as they had solar thermal heating on their pool (runs water through tubes that are heated by the sun) which required it to run throughout the day.  This works very well with NBT since again we want to minimize solar exports by running it through the day.


Little things that add up: I power my garden tools by the sun having replaced all outdoor tools with battery operated ones (charge the battery during the day). I dry my fruit with the sun (run my dehydrator during the day), and I run my ponds during the day with solar power. 


Summary:  Some folks I work with have no interest in changing how they use power, for them the answer is a bigger storage battery or a higher PG&E bill.  This blog was written for those who want to minimize upfront costs on a large battery, and further reduce PG&E charges by making slight changes to how they use power.  The key is to minimize exporting power under NBT and with a few changes this can be accomplished.  Join the club of “living and driving on sunshine”.

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