Making Sense of Your Solar Production: Where do the kWh’s go?

Making Sense of Your Solar Production: Where do the kWh’s go?

Keeping track of your kilowatt hours

Now that your solar system is producing, you might be wondering how the power flows from your panels and on to the grid. The most common questions we get are about tracking the kilowatt hours produced, why the numbers from Xcel Energy do not always match, and how the solar credits get used up.

When your panels produce power, they go through your production meter first. This meter is owned by the homeowner and starts at zero when the system is connected to the grid. It shows cumulative power produced. If you are on a program such as Xcel Solar*Rewards, the Made in Minnesota Solar Incentive Program, or an SREC program (also known as solar renewable energy credits), the production meter is where the total annual kWh credits will be electronically read. The production meter is not affected by usage from the homeowner.

Next, your solar power runs to your home electrical panel and is used by any electrical devices in your home that are on at the time. If you use all the power being generated at the time your solar is producing, the power never makes it to your utility bi-directional meter. The utility cannot track the used power from your solar system. To them it would be the same as if all the power was shut off in your home.

If you generate more than you use, that power goes on to the grid. The bi-directional meter keeps track of the credits and, when you are using more than you produce, you use up those credits.

Every month, the credits roll over unless you request a credit check from the utility. Some utilities have a true up period where you must take the credits as a payment. This varies by utility provider and region, so it is best to call your utility to see how they handle credits.

How Solar Power Works

  • Panels generate power as DC – direct current
  • Your inverter(s) convert the power to AC – alternating current
  • Your production meter keeps a running total on kWhs produced
  • The AC power goes into your home and gets used up
  • Any extra power goes on to the grid as a credit
  • When you use more power than you generate, you use up the credits
  • When credits are used up you purchase credits from the utility
  • Remember, if you use up the kWhs before they get to the meter, the utility never “sees them”. Instead of getting charged for the Kwhs from your utility you are using the power from the solar array.
  • Utilities are working on formatting bills to accommodate for reporting solar credits. Each utility formats their bills differently and you might have to compare the production meter and the usage or check wit your provider to see how to figure out the banked solar credits.
  • Yes! Both Minnesota and Wisconsin have net metering laws that require utilities to buy the power produced by your system for the same price that you purchase the power from the utility. Xcel participates in net metering. Smaller utilities and co-ops have the option to participate and may only give a wholesale price (2-3 cents per kilowatt) or no credit at all. The co-ops have to buy their power from larger utilities and do not have the margin to offer big discounts on power generated by solar or solar rebate programs.
  • If you are participating in an Xcel program such as Solar*Rewards or Made in Minnesota you are already “selling” your SRECs to the utility. After the production period, usually ten years, you are free to sell your SREC’s. Right now there is no open market in our area to sell your SRECs but there may be in the future.
By |2017-08-10T12:23:09+00:00June 9th, 2017|Categories: Frequently Asked Questions|Comments Off on Making Sense of Your Solar Production: Where do the kWh’s go?