We are starting to see a steady stream of requests for EV chargers and have been busy looking at the market to see what works and what doesnt. Its safe to say that not all chargers are the same.The key difference from a solar perspective is ‘Solar Surplus’ which allows you to charge your car off export solar rather than sending power out to the grid. This allows you to charge your car at a opportunity cost equal to your export rate which is generally going to be 6c. If your system is ramped or export limited it is 100% free.For those of us who can only charge on weekends a high speed solar surplus charger is essential. This will allow you to pump maximum charge into the car based on your schedule. For customers that work from home, the speed isnt as important but the solar surplus is.Generally speaking car chargers do not come with Solar Surplus as standard and many do not come with it at all. From our end we recommend Fronius for both string inverters and car charging systems. They have both residential and commercial solutions available.
Were the demons in the media right? Its still too early to say but we are defiantly seeing an increase in the number of grid voltage issues which cause solar inverters to drop offline. This issue is caused by solar inverters themselves as the inverter raises the voltage slightly to enable export to the grid. In periods of strong sunshine there is a lot of voltage rise going on which can cause inverters to drop offline for safety reasons.
The grid is in constant flux and this been the case well before solar was a thing. In simple terms if you add supply onto a congested network the voltage will rise. Add demand and the voltage will reduce. Energex and other operators have the task of continually tweaking local transformers and sub stations to try and iron out an amicable solution for all. If there is one thing that is certain, its never the same and its never consistent.
Recently we have seen further controls implemented to allow ramping of inverters during tough grid conditions. The regulator has also foreseen conditions difficult enough to suddenly require the dreaded ‘GSD’ device. This is a measure of last resort and whilst there is a media frenzy around this technology we see it as something that will be used momentarily on a couple of days per year and eventually not at all. Despite what you may be getting told, we do not see it as a valid consideration when purchasing a solar system large or small as the effect is negligible.
We are now installing both the Enphase battery system as well as the new IQ8 series micro inverters. The IQ8 micro inverters are primarily designed for larger wattage panels such as Jinko’s 475W Tiger N series which has become very popular on installs where roof space is at a premium.
Generally speaking we have moved on from Mono P panels and are now installing the latest Mono N chemistry by Trina and Jinko. The Mono N chemistry was first pushed forward by LG but is now more readily available and offers staggering wattage, and better performance in both low light and high temperature conditions. In the Trina range we can also offer a double glass product which offers greater hail resistance.
We are currently working feasibility on a 30kW/200kWh containerized power solution with shipping to Hawaii. This significant power cube will be connected to a water treatment plant on a remote island further enhancing community.
We are also steadily building experience in the area of larger format batteries suitable for functions such as demand shifting. This allows for those on demand tariffs to reduce peak demand charges.