How Utility Time of Use Net Meters Affect Your Solar System

Technology has advanced now to the point that utilities can now have the ability to monitor and control your electric consumption minute by minute rather than monthly. So many utilities are installing “Time of Use” net meters at customer locations who have previously built solar photovoltaic systems in a back handed way to make the solar system less valuable as measured by dollars and cents.

As a solar photovoltaic owner you are not helpless in regards to the utilities endeavor to get you to pay more for power, but you do need to understand the basics of the attack. “Time of Use” is exactly what it sounds like, and the utility will charge more for power during times of the day they determine to be peak load and pay less for the power you make that they consider to be off peak.

So first you need to carefully read about your utilities plans for times of use charges and be smart when you consume power. Second you need to adjust some of your habits to use more electricity during the peak hours your solar system is producing at its maximum or later in the evening when the utility is selling electricity at a cheap off peak price. The third tool you have is to add some solar panels to your existing system or when building a new system design it larger than what you needed before time to use meters came into existence.

For those that may have forgotten or not yet learned what “net metering” means, in the simplest terms it is a bi-directional electric meter that will spin forward when you take electricity from the grid and spins backward when you are over producing and giving electricity to the grid. Time of Use Net Meter mean that the energy consumed or produced will have a different dollar value based on the time of day your meter is spinning forward or backwards. A kilowatt/hour (kWh) of power is still always a kWh, but the value of that kWh changes throughout the day and or season with these smart electronic meters.

Let me share with you an example to help illustrate what the power company is attempting to do to your solar power and its relative value to you.


Let’s assume your utility has designated the peak period of the day as being from 4 pm to 8 pm weekdays. The power company knows people are coming home from work, making dinner, doing laundry, turning on the air-conditioning, and perhaps charging their new EV.

  1. Let’s say your utility will charge .20c/ kWh during this peak period.
    • Remember this is the time of day when the solar pv system is either not producing any power {winter} or producing very little)
  2. Now for simplifying this example lets say 10am- 3:59pm is mid peak that the utility has decided electricity is not worth that much during these hours so they will designate this time frame as .10c/kWh.
    • Coincidentally this is the power band time of day when most solar production is at its peak.
  3. Still keeping this simple, lets say your solar system produced 30 kWh during the middle of the day when electricity is only worth .10c/kWh
    • If no one was home and the house was not consuming any of this power and all of the electricity went to the grid via your net meter the value credited to you with these new fancy meters would be 30 kWh x .10c = $3.00.
  4. If you come home after 4pm and start using a lot of energy and consume 15 kWh of electricity from your power company (the sun is low and the solar is not producing) before going off peak at 8pm you will never get any electricity in your solar bank to get you through the night hours and winter low production months.
    • 15 kWh used x .20c/kWh = $3.00 during peak
    • So by consuming only half the energy during the peak period than was produced all day, during mid peak, your power company would be able to wipe out any solar credit you would hope to build during the day.
    • Thus effectively removing the likelihood of photovoltaic owner’s being able to fill their solar bank to combat the winter low production months.
    • Your utility would have affectively received twice the energy from the customer’s photovoltaic system during the day than your utility provide during peak hours, but yet the dollars would be a wash in value.

Years ago a kWh was kept in one’s solar bank as a kWh but then power companies wised up and started converting any energy they receive from a solar system’s over production into dollars/cents based on the value at the time that the power company received the extra energy. Without these new smart time or use meters they could only do this conversion monthly after reading the meters and thus putting excess energy in the customer’s solar bank ledger. Now with these new meters they can do this conversion instantly for any and all energy spinning the meter in either direction.

What can we all do to combat this scheme by the utilities, outsmart the system:

  1. Program your Air-conditioning to super cool your home from 2-4pm while rate are lower and your photovoltaic system is cracking out free power. Then at 4pm, if that is when peak starts, let the A/C coast and just circulate the cold air you produced earlier.
  2. Do laundry before 4pm or after 8pm. If after 8 you can get electricity back at a substantially lower rate than you provided it to the grid before 4pm and perhaps double your investment.
  3. Charge your EV after 8pm & also get cheap electricity back at a substantially lower rate than you provided it to the grid before 4pm.
  4. If you have a battery backup system, have it programmed to discharge during peak hours and charge it back late at night with cheap off peak electricity.
  5. Lights and TV’s don’t consume much power so I would not worry about them.
  6. Cooking is the only variable that you may not be able to avoid during peak times. However, if you can use a grill more often or slow cooking system to limit the oven use you can win hear too.

Hence, we all need to be smarter as to how we consume electricity and or build larger solar photovoltaic systems to combat this abuse by the utilities using smart meters with time of use charges. While I have never before advocated building systems larger than a home’s historical consumption I now recommend that systems be at least 120% of historical consumption to combat some of this time of use abuse. If an EV is in the near future or electric hot water heaters then higher still may be warranted.

The utilities are always trying to thwart our efforts to make our own power and become energy independent, we just need to keep adapting as they place the hurdles in our path.


David B. Waldman
President, ARE Solar