Tesla Powers Kauai With 52 MWh Powerpack & 13 MW Solar Farm – Video

MAR 13 2017 BY MARK KANE 24

Tesla has just delivered its second largest energy storage system to date, a 52 MWh project for the Kauai Island Utility Cooperative in Hawaii.

The ESS consists of 272 Tesla Powerpacks, and is integrated with a 13 MW solar installation to secure power supply at night.

52 MWh Tesla ESS delivered for Kauai Island Utility Cooperative (via KIUC/Facebook)

“To achieve a sustainable energy future the world needs reliable, renewable energy around the clock.

The island of Kauai has an abundance of solar energy but it can only be used when the sun is shining. Kauai burns millions of gallons of fossil fuels annually to produce energy at night.

Until now. Tesla’s 52 MWh Tesla Powerpack and 13 MW solar farm will store solar energy produced during the day and deliver it to the grid during the evening hours to reduce the amount of fossil fuels needed to meet energy demand. This dispatchable solar project represents the first time a utility contracted for a system of this scale that stores and delivers solar energy after sunset.”

Tesla has signed a 20-year contract with Kauai Island Utility Cooperative to sell electricity at 13.9 cents per kWh, which is about 10% less than Kauai paid previously for diesel power plant (15.48 cents).

Bloomberg reports that consumers paid some 27.68 cents in December for electricity in the state.

Categories: ESS, Tesla

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24 Comments on "Tesla Powers Kauai With 52 MWh Powerpack & 13 MW Solar Farm – Video"

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It sounds like this solar is not connected to the grid, but is dedicated to recharging those batteries.

So a ~4:1 ratio is needed it seems (MWh to nameplate solar MW rating).

Would be interested to know what fraction of Kauai’s total night time usage this displaces.

4:1 of the array rating isnt the same as what’s necessary for an instantaneous MW need, in most utility applications. The ratio of solar STC rating to needed batteries would generally be higher, i’d think, for backup and the practical output of PV. Kauai has little variation, in demand, which on top of the high~15 cent diesel gen cost, made this project a great idea.

This appears to be different. The details are fuzzy, but it seems like the main goal is to reduce the usage of generators for night time electricity generation.

I’d assume they can easily drain the batteries every night. So that the 13 MW solar panels would be working all day long to recharge the batteries.

TM – the panels mostly charge the batteries since Kauai already has enough daytime PV to run the entire island. I believe the panels do feed into the grid during the early evening hours when output declines and the grid is no longer PV-saturated.

… and is integrated with a 13 MW solar installation to secure power supply at night

– the meaning is not clear, as it is not the solar installation which delivers power at night

The batteries deliver power at night.
The panels charge the batteries during the day.

Dunno, maybe the stars are really bright in Kauai, can power the panels even at night 😉

And, welcome to the future and the future is here Hawaii.

Renewable energy plus storage (plus sustainable transportation in EVs running off this power) and Tesla is leading the charge–literally!

Of course the shills, shorters, and haters and the regressive politicians they support will be gnashing their teeth over this.

Oh well.

Well to be fair pumped hydro is actually cheaper 😀

I’m all for the solar panels just question if batteries are currently the best option for them. Maybe in part but not wholly. Last I heard they had decided against batteries but obviously something changed their mind.

In any event it’s far better than shipping all that diesel and burning it.

Is it though? Such projects are difficult to permit and build. A nice thing about the batteries in that they can be installed in a matter of weeks.

Elon Musk told Australia that he could install a bunch of batteries in 100 days to solve a problem they have had or the batteries are free!

In the long run yes they are cheaper. No need to replace the batteries when they go bad, less loss, etc.. Pumped hydro plants last for decades (or more). Even when the turbines or whatever go bad you can swap them out and put new ones in or repair them. The up front costs are admittedly more but in the long run the power is cheaper.

The permitting process I am sure is more of a PITA for pumped hyrdo than batteries not to mention I don’t know how quickly it can buffer the grid. I think placing the batteries regionally can help buffer the grid and then pumped hydro can take over every night. They compliment each other nicely.

You’d think on Kauai they would be able to get around the permitting process a lot. There are a ton of uninhabited locations, a lot on privately owned land even they could do this but I’m sure some colorfully named bird has a nest near most of them. I don’t really understand all that. Everything has it’s costs but when you factor in the benefits you would think this would be a net positive by a long ways.

They will be building some pumped storage. But it has more siting issues and a longer lead time. For batteries you just need to ask whether you can build there. It’s a simple footprint challenge.

And AES has a system coming with price under 12c/kWh.

I expect that there will be more news of systems like these coming.

And oh, sorry but as usual Tesla gets all the credit when they didn’t actually lead the charge…


I mean come’on give credit where credit is due…

Interesting article, though it’s just talking about buffering a solar farm that has as much as 70% or 80% drops in output whenever a cloud passes by, which is an idiotic problem to have with solar power.

Why? The point of solar is the fact that it is supposed to be distributed – a vast majority of solar power is supposed to be generated on the roofs of homes and businesses. Concentrating solar into farms will drastically increase the variability to the point that they risk cost-effectiveness. Excellent example of a dinosaur industry trying to apply new technology. No sense.

Residential rooftop costs 3x as much as multi-megawatt installations. Kauai is trying to reduce prices, not increase them.

Since that article they’ve built other large-scale solar farms in other locations, getting the benefits of geographical distribution without rooftop’s extreme costs.

It is not 3X more. And besides, the residences pay for their own solar installations so the price doesn’t hit the utility.

The issue they have is the drop in customer revenue and handling more solar PV on the grid. But they’ve changed their tariff system to require people to either completely self-consume or just output a small amount of solar PV on the grid.

Not to mention I think there is now a friggin waiting list if you want to have a PV system and be connected to the grid!

Yes it is 3x more. I work in the industry and utility scale is now under $1/DC watt installed, which works out to about $1.20/AC watt. Last I checked, rooftop solar (not my industry) will still run you $3.50-$4 per DC watt, so even if you get a good deal at $3.60/AC watt or less than $3/DC watt, you’re at 3x before tax incentives. However, you are right that the utility gets the customer to pay a lot making the true impact a lot less than the full 3x for the utility.

Just a few years back, you’d be hard pressed to get a 13,9 ct/kWh price per kWh on the solar alone. Anywhere in the world.

Very impressive.

Even more impressive, Kauai recently signed a similar deal with AES at 11 cents/kWh. The AES installation is bigger, but the main reason for the lower price is component cost declines between the times the two contracts were signed.

Kauai is also planning a pumped hydro facility with more storage than Tesla and AES combined.

These prices are still too expensive for the mainland US. But note that SolarReserve recently signed a deal at 6.3 cents/kWh (unsubsidized) in Chile. That deal was for 24 hour power (vs. 4 hours of storage in the Tesla and AES deals). SolarReserve is solar thermal with molten salt energy storage. Their system is too large and intrusive for Kauai, but it works great in desert areas near large population center. SolarReserve is planning a 2GW plant in Nevada.

“to sell electricity at 13.9 cents per kWh, which is about 10% less than Kauai paid previously for diesel power plant (15.48 cents).”

Less price volatility, MUCH cleaner, and cheaper.

The future is here. Hawaii needs to push for 100% renewable. Add onshore wind, offshore wind, and some pumped hydro. And some geothermal on the Big Island.

Off-shore wind seems like the least “area constrained” solution due to the islands being, well, islands.

But the water gets very deep, very fast, since the Hawaiian Islands are mountains/volcanos rising up from the deep Pacific Ocean floor. In contrast, the shallow North Sea is home to numerous off-shore wind turbines, many of which are in water only 20 meters deep. The southern North Sea has a max depth of only 50 meters. While there are some shallow waters off the Hawaiian Islands, the vast majority is very deep water. There are some very shallow shoals west of the Hawaiian Islands, but they are a very sensitive area teeming with marine life.



Off-shore wind should be minimized. Costs have fallen, but the nature of building and maintaining at sea make it expensive. They really should go for maxing out solar and geothermal before touching it.