tesla's solar and battery project in hawaii: we do the math - battery energy storage system

Tesla released the world's largest battery announcement in the summer-
The South Australian storage system is characterized by the secrecy of key details.
Fortunately, while mystery and mystery still loom over the project, Tesla's solar panels and battery energy can be explored or inferred more
Storage deployment on Kauai island, Hawaii, launched earlier this year.
In fact, there's enough information right now.
In the words of Elon Musk
We can do math.
This is also inspiring mathematics.
Don't miss: Tesla's grand opening of the battery farm on Kauai island
Hawaii's solar scale while the big story is that Tesla's solution is cheaper than diesel, the bigger story is that it's cheaper despite using only two sources of energy
The actual production of solar panels and twice
The actual capacity of the three giants.
Half of VaticanTesla's Kauai project is made up of 55,000 solar panels, capable of providing 17 megawatts of peak power directly
Current power and 52 MW
The 272 Powerpack 2 s form of lithium ion battery in 44-acre site.
Bigger than Buckingham Palace (40 acres)
Smaller than half the Vatican (110 acres).
Note that while solar arrays are often referred to as 13 mw (AC basis)
17 MW confirmed by Kauai Public Utilities Cooperative (DC basis)figure.
Solid savingsTesla signed a contract with Kauai utility co-op to provide up to 52 MW of electricity to the grid every night.
Utilities agreed to pay a flat rate of £ 13.
The sun in this storage is 9 cents/kWh, about 10-
Percentage discount on electricity prices they pay from diesel generators. (
During peak electricity consumption, diesel fuel is still needed on the island
It doesn't need to burn that much.
In addition, even in Hawaii, it is cloudy and rainy occasionally. )
View: Tesla, SolarCity and Ta'u: Sun, battery, clean energy (video)(Nov 2016)
As for why Tesla can't sell electricity directly to the power grid during the day, Kauai's power grid can't absorb more solar energy at all: at noon, photovoltaic power generation can already meet the needs of more than 90% on the island.
Two of the three are not bad: the battery version on Tesla's website, with a rated power of 210 KW per Powerpack 2, is made of 16 Powerwall 2 s, and they are rated by themselves2 kwh.
That makes sense because 13.
X 16 = 2 KW at 211. 2 kwh.
That is to say, the absolute energy capacity of each Powerwall 2 is definitely higher.
The National Renewable Energy Laboratory estimates that the first generation power generation wall with a nominal capacity of 7 KW is 10-
Designed as a kwh battery that cycles to discharge 70%.
This will be similar to two-thirds depth-of-
Discharge used in Chevrolet Volt plug
Nickel is also used in hybrid powermanganese-
Chromium battery chemistryAt two-thirds depth-of-
Discharge, 210-
The kilowatt-hour output provided by Powerpack 2 means an absolute capacity of 320 KW.
Therefore, the absolute capacity of 272 Powerpack 2 s on Kauai island is 87 Mwh.
The rated capacity of the Powerpack is 57 Mwh, while the public-
The disclosure number is 52 Mwh.
These differences are instructive.
Judging from the initial energy storage announcement of 2015, Elon Musk promised a battery price of $250 per kilowatt.
Number of hours for large deployments, reiterated this figure in the lead
Until the recent project in South Australia. When the two-thirds depth-of-
Emissions are taken into account at a cost of $250-per-
The kWh of rated capacity turned into a much lower $170-per-
KWh of absolute capacity at module level.
Why would Tesla include a rated capacity of 57 megawatt hours, but only 52 megawatt hours are reported?
Additional batteries may be there to ensure that even after 20 years of battery degradation, the Kauai installation can still provide 52 megawatt hours per night.
Two of the three are not bad: Solar Buildings. The solar panels installed on Kauai island are fixed --
Tilt, which means they are installed at a fixed angle;
They don't follow the sun all day like some other big people.
The scale of solar facilities.
According to Lawrence Berkeley National Laboratory, three existing utility companiesscale fixed-
Operating more than a year of inclined solar projects on Kauai island, capacity factors of 20, 21 and 22% were realized respectively. (
The capacity coefficient is the ratio of the energy generated by the power plant compared to the maximum theoretical output. )
This shows that a 21-
For the PV in the Tesla Kauai project, the capacity percentage factor is a reasonable guess.
So 17 MW multiplied by 21
Percentage of capacity within 24 hours
The hourly cycle gives us 86 megawatts of electricity every day.
From the product specification, powerpack can convert DC input to AC output with an efficiency of about 90%.
It means 86 megawatts of the sun.
In the face of DC power, it should generate a power grid of about 77 megawatts.
For AC power supply. The up-to-
52 Mwh Tesla promises to sell the utility about two-per-night-
Of Tesla's 77 megawatt-hour power generation, 30 megawatt-hour expects its solar panels to harvest every day.
Very simple, the solar and battery array are very large --
But even so, the economy still works.
Daily changes, rain and cloud although Tesla provides up to 52 megawatts per day for Kauai power grid, it cannot do this in storms or rainy days.
To estimate these impacts, solar anywhere software from clean energy research generated a representative solar irradiance data year for Lihue, the Kauai region where Tesla's project is located.
To be transparent, you can view the data used in the analysis on the tinyurl. com/TeslaKauai.
The representative year of SolarAnywhere data shows that the global average radiation level is 5.
0 hours per day, equivalent to 21-
Percentage of capacity factor.
This is consistent with the data from the Lawrence Berkeley National Laboratory.
SolarAnywhere's data predicts that in the first year, Tesla will provide an average of 50 megawatt hours a day for Kauai utilities.
Thanks to the extra 5 MW battery storage, even at 10-
Percentage of solar panels and batteries
It is estimated that Tesla will supply 45 to 49 MW of electricity to the grid every day (
Depending on the specific situation of its operation strategy).
Assuming that Tesla's average grid contribution will decline from 50 Mwh to 48 Mwh over the next 20 years, Tesla will provide an average of 49 Mwh per day.
According to green technology media estimates,
During the installation of Kauai, the cost of a scale solar farm was about $1 per watt, which meant that the solar portion of the Kauai project cost about $17 million.
Thanks 30-
This means that the cost of the investment tax credit is about $12 million.
EPRI/Sandia National Laboratory survey December 2015 estimated operating and maintenance costs for utilities
Develop solar farms at $10 to $25 per kilowatt per year.
Use the $25 figure, so-
The so-called Operation and maintenance costs of 17 MW solar panels on the site will reach $425,000 a year.
Higher estimates are appropriate as the Tesla Kauai project includes battery storage and the panel itself.
The battery price on Kauai island is $250 per kilowatt hour, which costs about $13 million.
Tesla tends to price cabling separately from on-site support hardware, which could be equivalent to halfMillions of dollars.
The worst choice.
Case number for O & M costs, we will adopt the best case in terms of cabling and hardware costs and assume that they are basically free.
Put everything together in return
The former cost is about $26 million-
Solar Farm $12 million, Battery $14 million
Tesla spends about $425,000 a year and about $2 a year. 5 million. (
This is 49 megawatt hour, that is, x $0 at 49,000 KW.
139x365 per kilowatt hour per day.
25 days a year. )
Under these assumptions, Tesla's internal return on the Kauai project was 6. 2 percent.
Although for many industries, this will be unacceptable low, SolarCity-
Like the solar industry. used 6-
Discounted cash flow assumed percentage, Kauai started as a SolarCity project. (
For more details, please refer again to the spreadsheet linked above. )
This shows that the numbers are correct;
We may think that errors in various assumptions may have been offset against each other.
What about the extra sunshine?
Tesla's Kauai project can generate much more power than a battery for most of the year.
The same is true for future projects. What to do?
One option is to use excess power to separate water and produce hydrogen for fuel cell vehicles;
First hydrogen fuel station in Hawaii
On Oahu, this method will be fully used by community vehicles.
If Tesla's Kauai project could sell 20 megawatt hours or more, it could be forced to waste power every day to power a hydrogen battery, even if the project provides electricity at a discounted rate, its internal rate of return will also rise further.
This will create a scene of irony in which Tesla's ego
Interest in hydrogen fuel success-
Battery cars create a demand for hydrogen.
Tesla's Kauai project may give us an unexpected lesson --
Far from hindering our transition to renewable or zero energy.
Energy emissions in the future
If the hydrogen consumed by the fuel cell is produced entirely using renewable energy, the fuel cell can function.
The main lesson, however, is that Tesla has shown that combining solar panels with energy storage is not only in the future, but today, in an economic sense.
In fact, in Kauai, this combination makes sense even if there are only two.
Electricity and twenty thirty-two-
Thirty times the battery capacity is utilized.
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