Firsthand Observations of Renewable Power Options in Another Part of the World
Solar energy can provide an enormous opportunity for New Zealand, and they invested heavily in hydropower. What can we learn from another country's priorities?
The west coast of Te Waipounamu, New Zealand’s South Island, is one of the rainiest places on Earth; the Cropp River, which flows into the Hokitika River, has recorded an annual rainfall of 18 meters, with more than a meter of rain (over three feet) recorded in a 48-hour period from March 25 to 26 in 2019. Just over the mountains, places in the Otago and Canterbury districts receive less than half a meter of rain but more than 2,000 hours of sunshine per year. Having massive rainfall in the mountains and full sun on the central plain, within 100 kilometers of each other, provides New Zealand with an enormous opportunity to generate electricity from sunshine and store it in hydropower reservoirs.
New Zealand is ahead of the United States on the pathway to sustainable energy, thanks largely to the investments they’ve made in hydropower. In 2021, Kiwis got almost 30% of their primary energy from renewable sources, whereas in 2022, we Yanks were just 13% renewably powered. Even though electricity in New Zealand is already pretty clean, I wanted to try a small experiment to see if I could go solar to meet at least a little bit of my electricity needs while traveling around the country.
Solar-Powered Travels
Since arriving in New Zealand in October, I’ve been using sunlight to charge my phone and personal electronics. I brought along some solar chargers with battery backup for our camping expeditions but decided why not use them every day to see how well solar works in different areas of Aotearoa. The first thing I noticed is that portable solar chargers work everywhere (even in places like Dunedin and Hokitika, where the locals told me there isn’t enough sun to make solar power worthwhile—while also warning me not to forget to put on sunscreen even on cloudy days or I might get sunburned from the intense solar energy New Zealand receives).
The second thing I noticed is that my chargers require many hours—stretching into several days during cloudy weather—to recharge using their tiny built-in solar panels. To increase the recharge rate (shrinking hours of charging time to minutes), for less than $20 (delivered to New Zealand from China), I bought a portable solar panel that fits into a book bag and includes a built-in 5-volt USB output port. Anything that I could plug into a USB charger, I can plug into this little solar panel.
My solar gear has been working great to keep my cell phone and iPad charged up all over this beautiful country—from windy Dunedin to bustling Wellington to rainy Hokitika. Besides the fact that it works everywhere on Earth, another great thing about solar is how it can scale. My tiny experiment buying solar panels and batteries made in China to support my electricity habit can pretty much be scaled all the way up to supplying electricity for an entire country.
My smallest solar charger has a built-in photovoltaic module that is only 56 square centimeters; I can recharge its battery ten times faster with a USB cable plugged into my $20 solar panel that is 547 square centimeters (about the size of a sheet of paper). Back home in Maine, we have fourteen solar panels that cover 162,000 square centimeters of our roof (about the area of four ping-pong tables) that can power our refrigerator and many other household loads.
Rooftop solar is relatively rare here in New Zealand (I’ve run across a surprising number of people who believe New Zealand needs more fossil fuel and shouldn’t follow Australia’s example of covering homes with solar panels), but Lodestone Energy has built a 61,000 panel solar power plant in Kaitaia on the North Island and has secured resource consents for three more solar farms at Clandeboye, Mount Somers and Dunsandel in Canterbury on the South Island that could satisfy the electricity needs for more than 21,000 homes.
Once it starts getting serious about solar, New Zealand could install gigantic battery banks to buffer its daily solar generation curve, but this is probably not the best plan. Solar panels are cheap; batteries are expensive. What makes solar power practical for me is that I can collect solar energy all day, store that electricity in a battery, and then charge my phone or iPad whenever necessary. Since I’m using just a little electricity each day, the high cost of batteries isn’t a deterrent. But at the scale of powering an entire country, a more affordable plan for New Zealand’s electricity future would be to take advantage of its favorable terrain and rain to use solar power to pump water uphill, then let the water flow back downhill to generate electricity whenever needed (i.e., build solar farms and pumped hydro at utility scale).
NZ Ahead of USA on Renewables
New Zealand is ahead of the United States on its pathway to sustainable energy, although the two countries are traveling very different pathways. After inventing nuclear fission in the 1940s, the United States decided to commercialize nuclear power for electricity generation. We now have dozens of nuclear power plants with a combined power capacity of 95.8 billion watts (GW), representing over one thousand billion dollars ($1 trillion) of sunk capital costs and putting ratepayers or taxpayers on the hook for billions more in decommissioning costs.
New Zealand has zero nuclear power plants. One of their largest investments in electricity generation was the Manapouri hydropower station, harnessing the power of the tremendous rainfall in their southern Alps as the water flows from the mountains to the sea. Despite having fabulous solar resource availability, New Zealand generates only a minuscule amount of electricity from sunlight.
“Primary energy” refers to all the energy a country uses for residential, commercial, and industrial uses, including fuel burned for transportation and for generating electricity. New Zealand obtains almost 30% of its primary energy from renewable sources—13.6% from hydropower alone—and it hasn’t really started tapping into its enormous solar potential yet.
For the United States in 2022, all renewable sources combined provided a smaller share (13%) of primary energy than the 13.6% share of energy that hydropower alone provided for New Zealand in 2021. Rather than ramping up our hydropower to match New Zealand’s output, we are starting to solarize our energy supply. While New Zealand’s average annual solar power output was less than a few hundredths of a gigawatt in 2021, the United States solar power fleet in 2022 was pumping out almost 62 GW of power to provide a 1.85% share of our primary energy. Solar’s share of our primary energy will be growing rapidly—this is the global energy story of the next decade, but most people don’t know the train has left the station. Solar will squeeze out coal first; then solar and other factors (e.g., the transition to electric vehicles) will destroy demand for petroleum.
A final observation I’d like to share in this dispatch from the southern hemisphere is how to compare energy data internationally. New Zealand, like every other country in the world, uses the metric system. So they report their primary energy in joules—quadrillions of joules in their case. The shorthand for one quadrillion joules is a petajoule (PJ). The United States, for inscrutable reasons, uses its own system for measuring energy. Our government’s Energy Information Administration likes to report our primary energy use in terms of quadrillions of British Thermal Units (BTU). One quadrillion BTUs is equal to 1,055.06 PJ.
What’s really silly is that both New Zealand and the United States agree that energy per time is power, and the unit to measure power is the watt, which is one joule per second. We could get an easy apples-to-apples comparison among the energy use of countries if instead of reporting energy use as PJ per year (quadrillions of joules per 31.6 million seconds) or quads (quintillions of joules per 31.6 million seconds), they just converted everything to watts (1 joule per second).
Let’s do the conversion. Here’s how the two countries compare in terms of primary power (energy per year) expressed in watts:
2021 New Zealand: 20 billion watts (GW)
2022 United States: 3,357 billion watts (GW)
Now that the world is starting to build 3 GW solar farms that are expected to be completed in 24 months, it’s easy to see how New Zealand could completely meet its energy needs with solar power in the not-too-distant future. Assuming a 20% capacity factor, a 5 GW solar farm provides 1 GW of power. Twenty 5 GW solar farms in the sunny parts of its South Island would provide more than enough energy to power New Zealand’s entire economy. While they’re waiting for their politicians to notice that fact, my experience has been that Kiwis could start harnessing solar power today. There is plenty of sunshine to spare!
Dispatches from New Zealand
Every other week we’re sharing a dispatch from New Zealand, showcasing interesting sustainable practices that differ from how we do things in North America. The alternate week we’re continuing to publish our series of practical action guides.
Last year, we explored the pathway to sustainable movement, energy, and goods. We’re exploring the pathway to sustainable food for the next few weeks. From the standard American diet to a healthier plant-centered diet and from industrial farming to regenerative agriculture, stay with us on the journey to sustainability.
References and Further Reading
Te Ika-a-Māui North Island and Te Waipounamu South Island, Toitū Te Whenua Land Information New Zealand
Where the rain falls, Te Ara The Encyclopedia of New Zealand
Cropp River, Wikipedia
Overview of New Zealand's climate, National Institute of Water and Atmospheric Research Ltd
The future of energy in New Zealand, Energy Efficiency and Conservation Authority
U.S. energy facts explained, United States Energy Information Administration
‘Go hard and go big’: How Australia got solar panels onto one in every three houses, The Guardian
Consents granted for three solar farms in Canterbury, The Post
Pumped Storage Hydropower, United States Department of Energy Office of Energy Efficiency & Renewable Energy
Nuclear Power in the World Today, World Nuclear Association
Estimated capital costs of energy generation in the United States in 2023, by energy source, Statista
Backgrounder on Decommissioning Nuclear Power Plants, United States Nuclear Regulatory Commission
Nuclear Energy Prospects in New Zealand, World Nuclear Association
Manapouri Hydropower: Sustainable Awakening in New Zealand, Fred Horch
New Zealand, Global Solar Atlas
Why Doesn’t the U.S. Use the Metric System?, Britannica
World’s largest solar power plant in Philippines expected to finish by 2026, Reccessary
What is capacity factor and how do solar and wind energy compare?, WhatNextNow