Swapping Out Diesel For Solar & Batteries In The Amazon Rainforest

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Recently, we wrote about how affordability is now the primary driver of new renewable energy installations at both the grid and individual level. It’s a pretty simple calculus, actually. As costs go down, new renewable energy resources go up. Call it the law of the unseen hand or just good old fashioned common sense. It works across all political groups and cultural divides.

“Build a better mousetrap and the world will beat a path to your door,” a popular adage says. Solar and wind, coupled with battery storage, are that better mousetrap, which explains why people and nations everywhere are buying into renewable energy, both literally and figuratively.

The transition to solar is especially robust in places like Africa and Pakistan, where a traditional electrical grid is either unreliable or nonexistent. Another place where it is seeing significant growth is in the Amazon rainforest, where no conventional grid infrastructure exists. There, villages rely on diesel generators for their electricity.

Reliance On Diesel

The symbolism could not be clearer. In the midst of the most ecologically sensitive area in the world, snorting diesel engines are spewing carbon dioxide, nitrous oxide, and fine particulate pollution into the air, endangering the forest and the health of those who live there. Of course, this makes no sense, but when diesel generators are the only game in town, diesel generators are what people will use for lights, air conditioning, cell phone charging, and access to the digital world.

In many parts of the Amazon rainforest, there are no roads, so the diesel needed to run those generators needs to be brought in by boat. In all, there are about 160 local thermal plants and thousands of generators scattered around the rainforest. Brazil’s government spends roughly $2.4 billion in subsidies per year to support this system, according to the country’s National Electric Energy Agency.

But the tide is turning, so to speak. Bloomberg reports that solar panels and lithium batteries are beginning to transform the region, and are supplementing or replacing diesel completely. “We used to depend on diesel and lamps,” said Waldemir da Silva, a leader in the Três Unidos Indigenous community of about 40 families at the mouth of the Cuieiras River. The Village is located about 45 miles (72 km) from Manaus, the capital of Amazonas state, and accessible only by boat. “Today we have electricity 24 hours a day, without noise or smoke.”

Policy Support

The shift is being driven by a mix of federal policy, falling technology costs, and philanthropic initiatives to build microgrids. Brazil’s Ministry of Mines and Energy plans to add solar and batteries to diesel generators around the Amazon. Last year it approved an initial group of 29 projects that will serve 650,000 people and avoid 800,000 metric tons of greenhouse gas emissions by 2036, according to official estimates. Subsidy savings are projected to total about $171 million.

About 1.2 million people live in Indigenous and riverside communities deep in the rainforest. They turn to generators but run them only a few hours a day to save fuel, which has only gotten pricier amid global supply disruptions from the Iran war. Until recently, this was the case in Três Unidos, a community of the Kambeba people that supports itself through eco-cultural tourism.

Its electricity came from a diesel generator that ran intermittently. A federal program called Luz Para Todos (Light for All) had supplied residents with solar kits and batteries, but these provided enough energy only for minimal lighting, and not enough for refrigeration. Without the ability to store food, residents depended on costly ice. “All our profit went to buy ice,” said Neurilene Kambeba, who runs a restaurant and a guesthouse.

Hydropower In Brazil

The national grid in Brazil is powered mostly by clean hydropower, which helped it keep its carbon emissions to a a minuscule 0.04 tons per megawatt-hour in 2025. However, emissions in isolated systems that rely on thermal generation and diesel engines produced 0.67 tons per megawatt-hour — 17 times more than the primary grid.

“We are reaching a point where climate change is beginning to endanger the very solutions we are proposing,” Joice Ferreira, a researcher for the Brazilian Agricultural Research Corporation told Bloomberg’s Fabiano Maisonnave. That’s why using batteries and solar panels is so important.

Growth Of Renewables In Brazil

Wind and solar have seen impressive growth in Brazil in recent years. In 2024, they combined to generate 24% of Brazil’s electricity. In 2019, they provided 9.9% of Brazil’s electricity. Solar has grown from 1.1% in 2019 to 9.6% in 2024. Wind has increased from 8.8% in 2019 to 15% in 2024.

While hydropower remained Brazil’s single largest source of electricity generation at 48% in August 2025, it was only the second month on record where it was responsible for less than half of Brazil’s electricity. Total hydro generation fell to 27 TWh — the lowest value since August 2021 — as reduced rainfall worsened Brazil’s dry season output, which was already worse then normal.

Growing demand and stagnating hydro capacity have led to a decline in hydro share in Brazil in the last decade. Moreover, hydro’s role in the mix also has changed. A former load base provider, dispatchable generation from hydropower stations now complements the variable output of wind and solar.

Think of hydro in Brazil now being equivalent to the concept of “spinning reserves” so popular in the US. Higher wind and solar output means hydropower plants can reduce their output during drought conditions and preserve water, enhancing system resilience.

Lower Fossil Fuel Use In Brazil

Despite weaker than normal hydro output, electricity generation by fossil fuel powered thermal generating plants provided just 14% of Brazil’s electricity (7.8 TWh) in August 2025. In previous drought years, such as 2021, fossil generation spiked to 26% (13 TWh) in August. Brazil’s successful diversification of its electricity mix in recent years means that wind and solar power are now able to compensate for the shortfall in hydropower without risking costly fossil fuel spikes.

Brazil’s buildout of wind and solar power has been fast enough to meet and exceed growth in electricity demand over the last decade. That has reduced the need for additional fossil generation and prevented an increase in power sector emissions.

As reported in the Global Electricity Review 2025 published by Ember earlier this year, Brazil’s emissions from electricity generation peaked in 2014 at 114 million tons of carbon dioxide. Between 2014 and 2024, wind and solar increased by 15 times, adding 168 TWh, which was enough to exceed demand growth. Because of renewable, fossil generation fell by 64 TWh, which resulted in a 31% decrease in power sector emissions,

Risk & Reward

Brazil’s rapidly increasing demand for electricity presents both an opportunity and a challenge, says Ember. The ability to meet that challenge with low cost clean energy from solar and wind is justification enough for the policy and investment strategies that support further increases in renewable energy. The continued buildout of clean power at pace can help avoid a rise in costly imports of coal and gas to meet rising power demand.

“Brazil has established itself as a global clean power leader. Diversifying its electricity mix has made Brazil more resilient against droughts while meeting the fast rising power demand of a growing economy without deepening its dependence on costly fossil fuel imports,” said Raul Miranda, the global program director for Ember.

The takeaway here is that renewables like solar and wind can work with other energy sources like hydro in a symbiotic relationship where one supports that other — something many of us may not have realized previously. It’s just another reason to embrace renewables, especially if they permit transitioning away from using diesel generators.

The Brazilian rainforest is the last place a diesel generator should be used. In fact, as the cost of renewables and batteries continues to decline, renewables are fast becoming the first choice for rural communities without access to a traditional electrical grid.

Fossil fuel apologists like to crow about how they have lifted millions of people out of poverty, but if doing so makes people ill or destroys local habitats, that is rather a weak argument when there are better — and cheaper — alternatives.