Hawaii has a high level of solar grid penetration at around 12%. For context, Australia is already at greater than 20% and growing and a number of areas have solar on more than 40% of roofs.
Now despite what the luddites will tell you, this is not necessarily a bad thing. There have been plenty of studies and are plenty of cases where grid stability is being managed well even with high solar penetration. However, the reality is that such high penetration levels, solar can cause problems if networks don’t adapt, typically with voltage rise. In Hawaii, the issue was to do with varying network frequency levels.
With varying frequency levels and lots of solar, the Hawaiian network was in a lose-lose situation because (like Australia) they had set the frequency and voltage windows very tight on solar inverters to “protect” their grid. The reality is of course in high concentration or where geographic clusters of solar exist (like Australia) if the network frequency drifts out of spec then the inverters drop off-line causing spikes in demand and more voltage and frequency drift. I like to think of it as a Pyramid Style Self Induced Death Spiral.
In the case of Hawaii, that means that 140MW or so of generation could suddenly snap off then back on-line. Not ideal.
So here is where network operators have two potential decision pathways. 1) Make the rules tighter, slow down the solar uptake and try to ignore the problem away (like Australia). 2)Collaborate, innovate and take advantage of every possible technological solution you can.
In Hawaii they chose the second option and due to the fact that around 60% of the islands’ solar is Enphase equipped, calls were made. Chats were had. A new, smarterer solution was talked about.
HECO had looked at the option of manually reprogramming inverters, but as you can imagine service call costs to 51,000 solar homes equipped with 800,000 micro inverters quickly added up to tens of millions of dollars. Uniquely, Enphase (who are heavily data focused and driven) already had the ability to remotely connect to and tweak inverter settings. Could they simultaneously, remotely and precisely make this change? And measure its effectiveness? From their headquarters in Napa Valley, California?
Yes they could.
So, the other day someone in a backroom in Enphase HQ quietly pressed the enter button and changed the settings on 800,000 inverters across 51,000 homes. No truck rolls. No field calls. No dogs to navigate. No chatty retired engineers to talk to. One guy and a computer.
To the best of my knowledge (anyone?) a change of this importance and relevance and scale has never been done before. Ever.
Benefits? One or two.
Firstly, tens of millions of dollars of expense were avoided which will implicitly avoid that cost needing to be passed on to customers. So Enphase theoretically just helped to keep the operating cost of the networks down, and the retail price of electricity too.
Secondly, although materiality is unclear at this point, by riding through more events rather than shutting down at the whiff of a drift in frequency, 800,000 solar inverters will be on-line for more time. That delivers better yield and more savings for consumers and in the case of Hawaii, less oil burned for conventional generation. So they just made more money for their customers.
Third, Enphase’s clever little solution saved the network a whole lot of money, because they had the data, the tools and the technology handed to them on a platter by someone else, which improved the reliability of their network asset.
This is an example of simple, effective and rapid collaboration with real benefits that spread across the entire value chain. Whilst we are seeing some signs of interest down under, there is plenty of room for improvement.
We have the technology.
It is real.
It does work.
Lets just get on with it, shall we?