I attended the Rebuild Hawaii Consortium quarterly meeting last week. I had never attended any of their meetings before, and I was somewhat surprised at the sizable number of people in attendance (40? 50?). It was held in a large stadium-style conference room at the Hawaii Convention Center. I had checked the agenda in advance, and thought I could arrive at 10 AM and still see everything I wanted to, but apparently the agenda changed since it was posted on the website.
The talk I missed that I wish I had seen was by Luis Vega on the Hawaii National Marine Renewable Energy Center. His slides look very interesting, lots of hard-nosed cost comparisons of wave and OTEC electricity generation.
Paul Norton have a talk on Zero Energy Buildings, which was interesting. I attended his REIS seminar where he covered some of the same things, but this was focused on ZEB. Some points I found particularly interesting:
- The introduction of air conditioning leads to a 70% increase in electricity use
- The key conceptual shift is thinking about the monthly cost of a home being the mortgage + utility bill.
- The efficiency / photovoltaic balance point is the point at which adding generation via PV is the same cost as additional efficiency measures
- A cost neutral design (monthly cost is same as a home built to code) that uses efficiency and PV results in an 85% reduction in home electricity usage
- Once major efficiency measures are in place (solar water heating, efficient lighting & air conditioning, insulation), the major remaining load is appliance plug loads
- In one military housing complex on Oahu, there is a 4x difference in electricity usage between houses with identical efficiency measures. Presumably the differences are due to appliance purchases and behavior.
- In a group of homes in Las Vegas, the difference was 5x
- Further, the differences were fairly continuous: there is no nice average plateau
- PV inverters on the neighbor islands have been causing problems because the utility frequency can sag during periods of high usage. By default, the inverters are set to disconnect from the grid when the frequency drops below 59.3 Hz, so inverters all over turn off, which puts additional strain on the utility, exacerbating the problem. Reducing that threshold frequency to 57 Hz can help. Thus there is a lot of research still to be done on renewable integration.
Another presentation was on HCEI and smart grid initiatives at PACOM. They are working on a project called SPIDERS that is trying to address the fact that access to electricity is a critical need for the military. One thing I was stunned to learn was that people living in military housing don’t pay for electricity! Thus they have no financial incentive at all to reduce their energy usage. Slide 8 shows an actual graph of HECO’s demand and generation for one particular day. Our work on OSCAR was all based on vague outlines of what the demand curve looks like, so it was great to see it “in the flesh”.
There was a lot of good information at the meeting, so I’m planning to attend in the future. Next meeting is June 2.