Is Solar Right for You?
A conversation with Jonah Knapp, KIUC Associate Engineer
To learn more about curtailment and right-sizing, please visit our website at https://www.kiuc.coop/rooftop-solar or call us at 808-246-4300.
Q: KIUC has seen a significant increase in rooftop solar installations during the past 10 years. There are many options for home and business owners. Can you give us an idea of the kinds of things a member might think about before deciding to install a system?
A: There are quite a few benefits to going solar, so a member should first identify what they’re trying to accomplish with their new photovoltaic system. This can include saving on their monthly electric bill, further reducing their personal dependence on fossil fuels and, if their system includes a battery, providing backup power to their home in the event of an outage.
Every member’s situation is different. KIUC is happy to talk to our members during this early evaluation stage to help them come to the right decision for their individual needs and goals.
Q: Are there any trends you’re seeing over the past two years on what type of systems members are choosing?
A: We’ve seen a much higher prevalence of batteries included in system designs. In 2019, only 40% of new PV systems included a battery. By the end of 2021, that percentage shot up to about 80%. Batteries can be a benefit, but they significantly increase the cost of the PV system. Members should carefully consider whether batteries make sense for them before they make such a large investment.
Q: What are the biggest pitfalls members should be aware of before they decide which type of rooftop solar system is right for them?
A: Pricing and payoff are the biggest considerations. If cost savings are essential to a member, installing a battery may not always make sense. Due to the high upfront cost, the payoff period for a PV system with a battery can be much longer than one without. It’s important for members to weigh their options and understand how their energy consumption behavior can determine what system is right for them.
Using our SmartHub app can give members great insight into how they are consuming energy. As an added resource, members can also call on our energy services department to see how much efficiency they can gain before even turning to solar.
Once members decide a PV system is right for them, there are many contractors on Kaua‘i from which to choose. Ask your friends for references, check with the Better Business Bureau and always feel free to check with KIUC early in the process so we can better prepare you for the questions to ask of your solar contractor.
Q: Are batteries always a good idea? Why or why not?
A: It really depends on the member. If they’re concerned about outages, batteries can offer immediate benefits to a member’s home via backup power. Furthermore, batteries allow PV systems to continue generating electricity in the event of an outage, something that isn’t possible without a battery.
Still, these benefits come at an added cost and may not pencil out if a member lives in an area where outages are minimal. It’s important to consider the average KIUC member was without power just 2.77 hours for all of 2021. That equates to 0.03% of the year without power, or 99.97% reliability.
Q: Many members want to “oversize” their system to sell electricity back to KIUC. What are the considerations to keep in mind when thinking about an oversized system?
A: While it would be great if we could allow members to generate and sell back as much power as possible, this is simply not a viable option due to the adverse effects it can have on the electrical grid. Overgeneration, which occurs when the supply of power exceeds the demand we have on the grid, can lead to a slew of problems no one wants: voltage spikes, unstable frequency and even outages. As more and more members install solar, the concern of overgeneration increases.
In 2015, to counterbalance the potential effects of overgeneration, we introduced our right-sizing guidelines. These guidelines streamline KIUC’s interconnection process and establish the amount of solar generation that members can install with no restriction by KIUC. If the member’s photovoltaic system contains a battery, this right-sizing depends on the battery’s storage capacity. Otherwise, we base it on the historical usage data at the member’s service address.
For most people, the quickest payback will be a right-sized, solar-only system. Nevertheless, members do have the option of oversizing their system above our right-sizing. If a customer wishes to do this, we require the installation of a curtailment meter on the oversized portion. This meter allows KIUC to disconnect that portion of the system from the electrical grid when there isn’t enough load for all the solar being generated. For context, last year we curtailed on 56 separate days, for an average of four hours on each of those days.
It’s important for members to do their research on our Schedule Q rate—applicable to oversized systems—which changes monthly based on the price of oil. As we move closer to 100% renewable, that link to oil pricing likely will be diminished, making Schedule Q rates less lucrative. The payback analysis from solar contractors should include all of these factors, but members should seek advice from multiple sources, including KIUC.
Q: What’s the best way to approach the decision to install a solar/PV system?
A: We recommend you call KIUC before you start, so we can answer questions and refer you to important information available on our website. Once you’ve chosen a knowledgeable contractor, they should be able to guide you through the process. We’re happy to work with your contractor to ensure a seamless process.
Once an interconnection application is filed, our goal is to turn it around for our members as soon as possible. If you’re concerned about the length of time it’s taking to get through the process, feel free to call us to inquire about the status of your application. KIUC is always happy to assist our members with the best possible solutions to their energy needs.