by Daniel Berry //

If you’re a homeowner in Massachusetts with a photovoltaic system, net metering is the process by which the utility tracks how much energy you import from the grid vs. how much you export to it. You export solar-generated electricity whenever your PV system produces more energy than you are using at any given time—for example, when few appliances are running and the sun shines bright.

Many residential PV systems in our region produce a net electricity surplus from April through October. From November through March, when the days are shorter and the weather more unsettled, these households generally consume more electricity than they produce. It is useful to think about net energy surplus or deficit on a monthly basis because your solar production varies seasonally and because utilities bill you on a monthly schedule.

In the above scenario, a house with PV might expect to accrue a credit of $500 from April-October on its electrical bill. Between November and March, this home might incur total electrical costs of $500. Such a household would be said to have a 100% offset, meaning that its yearly solar production covers the entirety of its yearly electrical costs.

Some homes with PV systems repeatedly produce more energy than they consume. This might be the case if you installed extra panels in anticipation of buying an electric car down the road, or if you replaced energy-hogging appliances with more energy-efficient models. Such households are strong candidates for using a tool called Schedule Z. The Schedule Z is an accounting document that directs your utility to transfer a percentage of monthly solar-electrical credits to another household, business, or organization within the same region and utility. It’s a great way to donate some of the benefits of your renewable technology to other entities, or share the savings with nearby friends and family. It can be set up at no cost and adjusted up to two times per year.

If you own a PV system and have seen substantial credits accumulate on your electrical bill over a couple years, given us a call to explore how the Schedule Z can work for you.