Environmentalists’ views on crypto have evolved, but tensions remain. Many still criticize it due to Bitcoin’s energy-intensive mining—estimates suggest Bitcoin’s network consumes around 200 TWh annually, comparable to some countries’ total energy use. Proof-of-work systems, like Bitcoin’s, drive this, relying on fossil fuels in regions with cheap power. Ethereum’s shift to proof-of-stake in 2022 cut its energy use by over 99%, which some environmentalists see as progress.
However, skepticism persists. Some argue crypto’s overall impact is overstated compared to industries like transportation or manufacturing, while others point to renewable-powered mining operations as mitigation. Yet, for hardline environmentalists, any non-essential energy use is a target, especially when grids are strained or coal plants are kept online for mining. Some users defend crypto’s innovation, others call it an ecological disaster. No universal “hate” exists—it’s more a spectrum of concern tied to specific chains and practices.
Renewable energy in tech is a growing focus, driven by sustainability goals and cost savings. Major players like Google, Microsoft, and Amazon aim for carbon neutrality or 100% renewable energy by 2030 or sooner. Google matched 100% of its electricity use with renewables in 2022, using wind, solar, and hydro via power purchase agreements. Microsoft’s powering data centers with 24/7 clean energy in some regions, targeting negative emissions by 2050. Amazon’s investing in 400+ renewable projects globally, though its total energy mix still includes fossil fuels.
Register for Tekedia Mini-MBA edition 17 (June 9 – Sept 6, 2025) today for early bird discounts. Do annual for access to Blucera.com.
Tekedia AI in Business Masterclass opens registrations.
Join Tekedia Capital Syndicate and co-invest in great global startups.
Register to become a better CEO or Director with Tekedia CEO & Director Program.
Smaller tech firms and startups are also shifting—many leverage cloud providers with green options. Blockchain tech, like Ethereum post-2022, slashed energy use with proof-of-stake, though Bitcoin mining still guzzles ~200 TWh yearly, increasingly tapping renewables (e.g., hydro in Canada, geothermal in Iceland). Some praise tech’s green push, others call it greenwashing given ongoing reliance on non-renewable grids.
Challenges remain—intermittency of solar/wind, battery storage costs, and land use for projects. Still, renewables’ share in tech’s energy mix is climbing as costs drop (solar’s down 80% since 2010). It’s not universal—crypto mining in coal-heavy regions lags—but the trend’s clear: tech’s betting big on green to power AI, cloud, and beyond.
Ethereum’s energy shift came with its transition from proof-of-work (PoW) to proof-of-stake (PoS) in September 2022, known as “The Merge.” PoW required miners to solve computational puzzles, consuming vast electricity—estimates pegged Ethereum’s annual use at ~70-80 TWh pre-Merge, rivaling some nations. PoS replaced mining with validators staking ETH to secure the network, slashing energy use by over 99.95%. Post-Merge, Ethereum’s annual consumption is around 0.01 TWh, comparable to a small town.
This shift addressed environmentalist critiques, as Ethereum’s carbon footprint shrank dramatically. Validators now need minimal hardware—a standard computer versus energy-hungry mining rigs—making it feasible to run nodes on renewables or low-power grids. From 2022-2025 show eco-conscious users praising the move, though some argue it’s less decentralized than PoW. Critics also note that Ethereum’s fees (gas) and scalability issues persist, driving traffic to less green chains.
While Ethereum’s greener, its broader impact depends on adoption and whether validators use clean energy. Still, it’s a benchmark for blockchain sustainability, pressuring other networks to follow. Several blockchains have prioritized energy efficiency, following Ethereum’s lead with proof-of-stake (PoS) or other low-energy consensus mechanisms. Solana Uses a hybrid of PoS and Proof-of-History (PoH), enabling high-speed transactions (~65,000 TPS) with minimal energy—around 719 joules per transaction, less than a Google search.
Cardano: Employs Ouroboros PoS, using ~0.55 kWh per transaction, over 1,000 times more efficient than Bitcoin. Focuses on sustainability, with applications in supply chain traceability for eco-friendly goods.
Hedera Hashgraph: Uses a unique Hashgraph consensus, not traditional blockchain, achieving high throughput with low energy (~0.0001 kWh per transaction). Partners with the Crypto Climate Accord for carbon negativity.
Tezos: Runs on PoS with ~0.0001 kWh per transaction. Its self-upgrading protocol reduces overhead, and it’s gained traction for low-impact NFT platforms.
Polkadot: Uses Nominated PoS, enabling interoperability across chains with low energy use. Exact figures are scarce, but its design prioritizes efficiency.
Avalanche: Multi-chain PoS network handling 4,500 TPS, using ~0.0005% of Bitcoin’s energy (0.02 kWh per transaction). Popular for scalable, green DeFi apps. These blockchains leverage PoS or innovative mechanisms to cut energy use drastically compared to proof-of-work systems like Bitcoin. Some, like Solana and Algorand, also pursue carbon neutrality or negativity through offsets. However, energy efficiency varies, and “green” claims can depend on validator energy sources, which aren’t always renewable.