Enphase Energy, in their 4th quarter earnings call, made references to their upcoming ‘Ensemble’ line of solar inverters. Their Chief Product Officer, Raghu Belur, suggested that the new hardware will allow solar power to run a house – even without a power grid or batteries.
This is an interesting statement because almost all residential solar power inverters are designed to shut down for safety and technical reasons in case of the grid powering down.
Enphase is developing this residential on-grid/off-grid solar system out of their most cutting edge inverter technology as part of their grid-independent “Solar 2.0” technology. The ‘Ensemble’ line is included within this push and a feature in the new IQ8 line of inverters. One of the goals of Enphase as part of this push is to get the price of their inverters to a similar price as string inverters – 10¢/W.
In this attempt to cut microinverter costs by 50% to stay competitive, Enphase has continued a push to improve microinverter designs by increasing ASIC gates, maximum power, and by decreasing size/weight. For instance, Ensemble, which was announced June 19, 2017 and expected on the market in Q1 2019, expects to see 5 million ASIC gates in a 1.0kg package – versus today’s products that have almost half the gates and almost 40% heavier weights.
“Most customers are unaware of this limitation (automatic shut off) with today’s solar technology. So, to address this limitation we have invented a microinverter technology that is completely grid agnostic. This means that even if the grid fails and there is sufficient sunlight, the Enphase system will continue to produce energy and meet the demands of the home or business. The Enphase microinverter system’s capabilities further enhanced when the Ensemble technology is incorporated into our AC battery storage solution.”
To do this, Ensemble would need to provide electricity services that the broader power grid generally provides a solar system – like keeping the power grid frequency at 60 Hz. The below slide from their summer presentation definitely insinuates this capability. First Solar and the State of California verified that inverter technology could in fact offer these grid services without energy storage on a large-scale.
Enphase specifically mentioned that this hardware would be have been valuable to those in Puerto Rico after the recent hurricane, and that it was especially valuable to those in the developing world – 1.2 billion people – who have no access to a power grid.
The language here seems to suggests that the solar technology can work independent of a grid connection before it is associated with an AC battery solution. This is an interesting, and potentially significant statement to many, because most solar inverters are sold with an ‘automatic shut off switch’ that detects when the power grid goes down, and – to protect electricity line workers – shuts down the entirety of the solar power system.
During Florida’s recent hurricane, many homeowners were surprised to learn of this reality. In fact, it led to conspiracy theories that the power company had made it illegal to run while the grid was down. Snopes had to step in.
SMA has offered a piece of hardware it calls the “Secure Power Supply” (pdf) as an upgrade to its inverters that offers this no-grid/no battery electricity service. The hardware allows you to draw up to 1,500W of power, as long as the solar system was providing it.
In a complex moment, if you really wanted electricity, you could do some creative wiring to trick your inverter into thinking the grid was up, or you can buy simpler/small solar systems and literally plug them into an outlet. If this feature is added to the Enphase line of hardware, expect more groups to do the same.
Eventually, when we build large-scale solar-powered grids, this technology might be the default as its distributed energy systems that offer the grid its power.
Source of this knowledge – tweets from Electrek reader Orion Coates