Can You Have Too Much Solar? – Redux

I realized after my earlier posts on the solar power situation in Hawaii (Part 1, Part 2) that I had not done enough background reading. I was not wrong, per se, but had missed on some of the relevant context.

First, from Channel 2 KHON, that the Public Utilities Commission (PUC) had rejected Hawaiian Electric Company’s (HECO’s) Integrated Resource Plan (IRP). An IRP is typically a utilities long-term plan as to how it will continue and improve service in the coming years and decades. The PUC rejected the IRP, which is quite uncommon, believing that HECO ” is not moving fast enough to lower utility rates and connect more photovoltaic systems into the grid.” So, while there certainly are technical difficulties in connecting more solar, HECO needs to take much more action on solving those problems.

Second, Utility Dive provides a much longer overview of what HECO needs to do to modernize their network. One thing they point out is that this isn’t the PUC acting like a bunch of tree-hugging hippies, but that “the best path to lower electricity costs includes an aggressive pursuit of new clean energy sources.” The utility could install large solar PV facilities at a total cost of about $0.16/KWhr as opposed to about $0.23/KWhr for current generated power. So, HECO could provide solar electricity for about a third less cost than their existing oil-fired plants. Saving the planet is just a bonus.

Quick note: those aren’t electrical prices you will see on your electric bill, but raw cost of generation. From the Energy Information Administration, the average retail price for all US residential users is about $0.12/KWhr, while the average retail price for a Hawaiian is over $0.38/KWhr.

Can You Have Too Much Solar? – Part 2

In Part 1, I highlighted one technical issue with the increasing solar generation in Hawaii. Here, I want to discuss a misperception on an institutional barrier to distributed generation. When people think of electricity, they immediately picture their monthly bill and assume the utility makes all their money on the markup or profit margin per kilowatt-hour (kWhr) used. Like any good urban legend, that has a grain of truth. Consumers certainly are charged more for using more, but there are other utility costs that may or may not be rolled into that consumption rate.

The misperception is that Hawaiian Electric (HECO) is against solar because when more solar power is generated they do not sell as much electricity. But, that assumes the utility only functions on the hierarchical system where HECO just takes their cut in the middle:

• power plant –> transmission and distribution –> user

But, if HECO ran a fully functioning multi-directional grid, they could leverage temporal and spatial differences in generation and consumption. During the day, HECO would buy the excess power from the home solar panels and sell it to downtown office buildings or regional industrial users. At night, HECO would then buy or generate non-solar power for people to turn on the lights, cook dinner, and watch Game of Thrones. The raw material (electricity) costs balance out as they are buying from and selling to different parties in different places at different times. HECO would make their money charging people to be connected to this grid. There still will be consumption fees (use more, pay more), but HECO would now be incentivized to operate efficiently in moving power around, rather than just churning out more of it.

Much of this has already been going on for years and will continue for many more. Deregulation in the 1990s led to splitting utilities into generating companies and distributing companies. HECO has added a fixed rate charge to cover their capital costs so it is not buried in the variable kWhr rate. Other companies are experimenting with tiered pricing and time-of-day rates. Ernst & Young recently published a small pamphlet encouraging utilities to modernize beyond the old hierarchy.

Obviously, there’s much more to all this (and way above my head). A robust smart grid will not be cheap or quick to build. Renewable power is still a tiny fraction of all power production. Legal monopolies like utilities are forever in conflict with consumers and regulators. But, like I tell everyone when I discuss these topics – the technical problems are comparatively minor and totally solvable compared to these matters.

Can You Have Too Much Solar? – Part 1

Recently, I’ve seen several articles regarding problems with having too much distributed power generation (e.g., primarily home solar panels, but also small wind) on a utility grid. The best example is the Hawaiian Electric Company (HECO) restricting installation of new solar panels in residential areas. Most of the article headlines were dramatically portraying HECO as the evil utility needing strict oversight. (The bald-headed villain, sitting in a high-backed chair, stroking a white Persian cat, is merely implied.) Green Tech Media has a much more balanced overview of the situation including the technical challenges, which I’ll summarize here.

HECO is limiting (or at least delaying) new solar installations in neighborhoods where the daytime power generation exceeds the consumption. (Dark blue areas in map.) I emphasize daytime generation and consumption because this is where the conflict arises. Total electricity use peaks during the middle of the day when all the stores, offices, and factories are up and running. Solar generation peaks at the same time in the bright, mid-day sun. But, electricity use in residential areas drops as all the busy little worker bees are at those stores, offices, and factories. So, just a few solar panels will meet the daytime needs of a given neighborhood. If a couple of your neighbors beat you to the punch, you’re out of luck and probably peeved.

So, back to the question, Can you have too much solar? Yes and no (my favorite answer). The traditional grid system is hierarchical and unidirectional – from big power plant to distribution system to end-user. It is not built to handle flows in many different directions at different times of the day. So in the short-term, yes, too much solar could lead to problems.

Conversely, Hawaii is uniquely positioned to operate a renewable-energy smart grid due to high electricity costs (from burning imported oil), readily available renewable resources (ample sunlight, steady trade winds, and even geothermal on the Big Island), and relatively small size. In the long run, therefore, Hawaii can accommodate much more distributed generation. Until, that is, they generate more than they can use. But, let’s cross that bridge when we get there.

In summary, I agree with HECO in regulating the amount and size of new solar power to protect the overall system (regardless of any white-cat ownership). That doesn’t mean that I think the status quo is acceptable, but it does take time (and money) to transition to a better arrangement. In Part 2, I will cover the institutional and financial issues to get from the short term to the long term.