Top “Solar Superstar” in the USA – Watts Up With That?

Guest “Book’em, Danno!” by David Middleton

9 US cities now produce more solar power than the entire US did 10 years ago
Ben AdlerSenior Editor
Thu, April 21, 2022

American rooftop solar power is growing at a stunning rate, a new study finds, with solar capacity increasing 19% in 2021.

The United States now has 121.4 gigawatts of solar photovoltaic capacity, enough to power 23 million homes, up from just 0.34 gigawatts in 2008, according to the Department of Energy.

[…]

“The amount of solar power installed in just nine US cities exceeds the amount installed in the entire United States 10 years ago,” the report, titled “Shining Cities 2022,” found. In fact, 15 of the 56 cities included in the study increased their solar capacity tenfold since 2014.

[…]

Yahoo!

Ben Adler is the Senior Climate Editor for Yahoo! News. He has a BA in government. Apart from not actually being able to edit the climate, Mr. Adler also doesn’t seem to grasp a few simple concepts:

  1. Cities don’t produce solar power, the Sun does. Solar panels convert it to electricity.
  2. Installed capacity isn’t generation.
  3. The cited EIA link puts the capacity at 97.2 GW, not 121.4 GW.
  4. The most recent Electric Power Annual 2020, published last moth puts solar PV at 73.9 GW (75.6 if you count solar thermal), including small-scale installations.
  5. Rooftop solar accounts for only about 1/3 of the 121.4 97.2 75.6 GW of solar photovoltaic capacity.
  6. 121.4 GW of solar photovoltaic capacity would be “enough to power 23 million homes” for 6-8 hours per day, when the Sun is shining.
If it looks like a duck curve, swims like a duck curve, and quacks like a duck curve, then it probably is a duck curve.
“On a clear day you can” generate 8-9 hours’ worth of solar PV electricity.

Let’s assume that the aforementioned 9 US cities now have more solar PV capacity than the entire US did 10 years ago… So what? As of 2019, three states (TX+FL+CA) had more natural gas generation capacity than the current total US solar PV capacity.

Based on the US Energy Information Administration’s (EIA) annual survey of electric generators, natural gas-fired generators accounted for 43% of operating US electricity generating capacity in 2019. These natural gas-fired generators provided 39% of electricity generation in 2019, more than any other source. Most of the natural gas-fired capacity added in recent decades uses combined-cycle technology, which surpassed coal-fired generators in 2018 to become the technology with the most electricity generating capacity in the United States.

EIA

Capacity vs. Generation

Generator capacity: The maximum output, commonly expressed in megawatts (MW), that generating equipment can supply to system load, adjusted for ambient conditions.

Generator nameplate capacity (installed): The maximum rated output of a generator, prime mover, or other electric power production equipment under specific conditions designated by the manufacturer. Installed generator nameplate capacity is commonly expressed in megawatts (MW) and is usually indicated on a nameplate physically attached to the generator.

EIA

Actual generation, commonly expressed in megawatt-hours (MWh) is the actual electricity output that the generating equipment delivers to the grid. This varies widely by generation source. Nuclear power plants require very little downtime and routinely deliver 95% of their rated capacity. Natural gas combined cycle and coal-fired power plants can theoretically deliver 80-90% of their rated capacities, but usually only realize 40-50% because they react to demand and economics. They ramp up and down in response to demand. They also react to natural gas prices. Higher natural gas prices reduce natural gas utilization and increase coal utilization. Wind and solar power only deliver electricity to the grid when the winds and Sun cooperate. Wind generally ranges from 20-40% of rated capacity. Solar is generally in the 20-30% range.

Using data from BP’s 2021 Statistical Review of World Energy and the EIA’s Electric Power Annual 2020, we can see that, nationwide, solar actually fell below 20%.

2020 petroleum natural gas coal nuclear power Solar PV
Gigawatt-hours (GWh) 18,812 1,738,439 844,072 831,493 108,000
Gigawatts (GW) 27.57 485.81 215.55 96.50 73.89
Realized Capacity Factor 7.8% 40.7% 44.6% 98.1% 16.6%

I didn’t include wind, because it isn’t relevant to this post. I did include petroleum, because it is relevant to the next section of this post.

“Solar Superstars”

In his Yahoo! News article, Mr. Adler referenced this report: Shining Cities 2022, The Top US Cities for Solar Energy. Oddly enough, the report doesn’t seem to mention actual electricity generation and focuses exclusively on capacity. The report highlights a group of cities that they call “Solar Superstars”.

Some of these cities make a lot of sense: Las Vegas, San Diego, Phoenix, etc. It’s not unusual for solar PV installations in these sorts of places to realize 40% capacity factors during summers. However, the superstar of superstars, Honolulu HI, struck me as “funny.”

Hawaii Quick Facts

  • Hawaii was the first state to set a deadline for having 100% of its electricity sales come from renewable energy, which is required to be achieved by 2045. In 2020, the state’s power suppliers met the interim requirement that 30% of electricity sales come from renewables.
  • Despite being among the five states with the lowest total energy consumption, Hawaii uses about 12 times more energy than it produces. More than four-fifths of Hawaii’s energy consumption is petroleum, making it the most petroleum-dependent state.
  • In 2020, solar power provided almost 17% of Hawaii’s total electricity, primarily from the increase in generation from small-scale, customer-sited solar panel systems that nearly doubled since 2015.
  • In 2020, the amount of Hawaii’s coal-fired generation was the lowest since 1992, and coal fueled 11% of the state’s electricity generation. The state’s single coal-fired power plant is scheduled to close in 2022.
  • Hawaii has the highest electricity retail price of any state and it is nearly triple the US average rate, in part because the state relies on imported petroleum for 60% of its electricity generation.

Last Updated: February 17, 2022

EIA

Solar power might actually make sense for Hawaii… But…

“In 2020, the state’s power suppliers met the interim requirement that 30% of electricity sales come from renewables…”

February 2022

Generation Source Thousand MW % ofTotal
Petroleum fired 540 77%
coal-fired 61 9%
Nonhydroelectric Renewables 103 fifteen%
Total 704 100%

In 2020, the state’s power suppliers met the interim requirement that 30% of electricity sales come from renewables.

What happened since 2020? Or was January just a bad month for solar? There are no accessible data for rooftop solar performance in the Honolulu area, but the data for utility scale solar are easily accessible. Let’s look at one of the larger facilities in the area:

Plant Name: Waipio Solar
Plant Code: 60024
Utility Name: Waipio PV, LLC
Utility ID: 59764
City: Waipio
County: Honolulu
State: Hawaii
Sector: IPP Non-CHP
Technology: Solar Photovoltaic
Data Period: 202108
Primary Fuel: solar
Total Nameplate Capacity: 45.9 MW
Total Net Summer Capacity: 45.9 MW
Net Summer Capacity by Energy Source: Solar = 45.9 MW

EIA

Waipio Solar has a net summer capacity of 45.9 MW. It is located in the best solar resource area on Oahu:

https://solargis.com/maps-and-gis-data/download/usa

Yet, Waipio’s average annual capacity factor is only 20%, with winter being the worst wind season.

That said, Hawaii has very few choices when it comes to electricity. Petroleum, natural gas and coal all have to be imported. While they have significant geothermal resources, the only active geothermal power plant is on the Big Island and provides about 30% of Hawaii island’s electricity:

Hawaii Island purchases 38 MW of power from the Puna Geothermal Venture plant. PGV has permits allowing it to expand another 22 MW in the future at its current location. Learn more about Puna Geothermal Venture.

Possible geothermal energy resources may exist in West Hawaii and on the island of Maui.

No geothermal resources have been identified on Oahu that could be tapped for electricity.

Hawaiian Electric

Hawaii has an abundant wind resource and actually pioneered wind power back in the 1980’s…

Hawaiian Electric Pioneered Wind Energy Development

A primary reason for the formation of Hawaiian Electric’s parent company, HEI, in the early 1980s was to develop wind energy. HEI invested more than $25 million through a non-regulated subsidiary to develop a 9-MW wind farm at Kahuku. HEI invested another $7 million in a 3.2 MW wind turbine at the same location — the 360-ft. MOD-5-B – which was then the world’s largest horizontal axis wind turbine. The Kahuku wind farm experienced winds that were more turbulent than expected and mechanical problems with the first-generation turbines, resulting in low energy production. In addition, a dramatic drop in the price of oil made the wind farm too costly to operate. It was later sold to New World Power and has since been closed and the turbines dismantled, but the operations provided useful research information.

In the mid-1980s, Maui Electric hosted a 340-kW wind turbine demonstration unit for several years at its Maalaea facility. Maui Electric later purchased this wind turbine and operated it until the end of its useful life.

Hawaiian Electric

However onshore wind projects have faced considerable opposition and significant offshore wind power projects are many years down the road… So it looks Hawaii will be mostly stuck with imported petroleum and intermittent solar for the foreseeable future.

conclusions

Irrespective of how many US cities become “solar superstars,” petroleum and natural gas will continue to kick solar’s @$$ well into the future.

Is there any other way to close out a post on Hawaii other than with Steve McGarrett’s classic line from Hawaii Five-O?

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