As Florida moves to hobble solar industry, zero export solar PV is an option

Florida’s utilities have worked for years against renewable energy, spending millions on misinformation campaigns, high-power, high-access lobbyists, and political campaign contributions to maintain their monopoly on energy in Florida. Now, with the passage of (FPL-authored) HB 741, we are just a governor’s signature away from losing our vibrant solar industry in this state.

While we wait anxiously for the inevitable stepping down of net metering benefits as well as fixed monthly charges for solar consumers, there is an option for those who wish to adopt solar but would prefer to use ALL of the precious energy they produce rather than send it back to the grid.

Those considering the installation of a solar PV system have the option to use “zero export” (or “export limitation” or “feed in limiting”) PV and battery systems. These systems use inverter software controls to prevent power from being sent back to the grid. In its most basic form – solar without battery – the software monitors power flow at the utility meter (an additional energy meter must be installed at the utility meter to do this) and, if it senses power starting to flow back to the grid, it limits the output of the solar inverter. This takes place constantly and prevents the system from exporting power to the grid.

The upside is that the export limitation option allows you to use energy for self-consumption when the loads are high, while maintaining the export limit when the loads (energy usage) are low. There is a downside to this, too, unfortunately: it decreases the total output of your solar PV system, which lowers the return on investment.

Adding a battery, or batteries, to a zero export configuration can help by absorbing the excess power produced by the solar energy system. For example, Tesla has a function on its system called Self-Consumption Mode, which effectively does this but, once the battery is full, it does allow the export to the grid. Zero export is basically self-consumption on steroids. You discharge the battery at night, to reduce grid consumption, and then charge it during the day with the excess power from the solar PV system.
There is a downside to this, too: you have to add a battery, which reduces the ROI of the solar but, on the plus side, does add energy resilience/backup power to your home or business.

The big question is whether or not one would be required to have an interconnection agreement with the utility company, since you aren’t net metering. We would guess that FPL and the other utilities would argue that they would require an agreement but this is an open legal question. If you look at the process today, net metering is a voluntary program: homeowners notify their utility company that there is a new system being turned on and then the utilities make the customer jump through many hoops to secure the financial benefit. There is no requirement to provide this notification – you could have your system inspected by the building department and never notify the utility; the only way they would know would be to inspect satellite imagery to see that you have installed solar.

At this time, there is still an incentive to notify your utility that you have installed a solar energy system because, if you don’t and you export excess power, they actually penalize you by charging you for the energy you send back to the grid. With zero export, you wouldn’t be penalized that way and, in our opinion, would neither be required to sign an interconnection agreement nor pay any fees to the utility.

That brings us to the final point of all this: zero export is, frankly, not a good choice from a societal perspective (notwithstanding certain technical situations where it is necessary). This is an arms race between the utilities and homeowners and we already know what the outcome is going to be. As the technology not only improves and but also gets less expensive, we will reach a point where “defecting” from the grid (or, at least, doing zero export) is financially viable for more and more people. As that happens, it really doesn’t matter which policies are in place – we can’t imagine anyone could say that people should be required to connect to the grid if there is a viable and sustainable alternative.

What we really need, instead, is smart energy policy that encourages the utilities to work WITH homeowners to improve the grid, make it more resilient, and make it more environmentally sustainable because all of these batteries and solar distributed across the grid are actually a good thing for everyone on and off the grid. Sadly, misguided and self-serving legislation like HB 741 instead encourages people to look at alternatives – such as zero export solar.