Elon Musk recently revived the “51% renewables” benchmark, to report that the energy that underpins Bitcoin “cannot be imitated.”
The reference refers to his previous promise that Tesla would resume accepting Bitcoin payments once at least half of mining energy came from clean or low-carbon sources.
However, with the latest data suggesting the network may have crossed that threshold, Tesla still has not re-enabled BTC checkout. Why?
Has Bitcoin already passed the bar?
According to the Cambridge Center for Alternative Finance’s Digital Mining Industry Report 2025Renewable energy is now the driving force behind approximately 52.4% of Bitcoin mining operations surveyed.
Of this, 42.6% comes from renewable energy sources (hydro, wind, solar, etc.) and 9.8% from nuclear or other low-carbon sources. At the same time, contributions from fossil fuels have shifted: natural gas now accounts for 38.2% (from ~25% in 2022) and coal has fallen to 8.9% (from ~36.6%).

If Musk’s promise is taken literally, Bitcoin could already surpass the 51% “renewable energy” limit, at least as measured by Cambridge’s survey of companies that account for about 48% of global mining capacity.
But this is only half the story. The wording matters: Musk has referred to renewable energy sources (50%) in previous comments, although in later tweets he says: “51% renewable energy” or “energy you can’t fake.” The Cambridge figure lumps together renewables and nuclear; the share of pure renewable energy is lower (42.6%).
So BTC could still fall short depending on the rigidity of Musk’s definition.
Furthermore, the Cambridge approach is survey-based and only covers a subset of miners. Off-grid activities, limited renewables, regional peculiarities and temporary mismatches (when renewables produce more or less relative to mining demand) complicate the picture.
Alternative models, such as those based on grid carbon intensity or energy tracking, often provide more conservative estimates of the share of renewable energy. That difference means that even a nominal “pass” is subject to debate.
So why hasn’t Tesla flipped the switch?
Even assuming Bitcoin now qualifies for Musk’s sustainability test, Tesla has not enabled BTC payments again. A number of pragmatic and symbolic obstacles remain.
The first is due diligence. Musk previously stated that Tesla would only resume payments once he saw “reasonable (~50%) use of clean energy… and a trend to increase that number.” That wording implies he’s looking for perseverance, not a one-time data point.
A single report showing 52% renewable energy may not meet its requirement for a verified and sustained upward trend in Bitcoin’s energy mix.
Another factor is the clarity of the definition. Tesla would have to decide whether “sustainable” includes nuclear and low-carbon sources, or strictly renewable energy sources such as hydro, wind and solar. The Cambridge data combines these categories, but Musk’s earlier formulation specifically addressed renewables.
Without a universally accepted definition, any decision to resume BTC payments risks being accused of greenwashing.
There is also the issue of trader and market risk. Accepting Bitcoin exposes Tesla to price volatility, complex accounting treatments and potential regulatory complications.
Even if the company immediately converts the BTC revenue into fiat, fluctuations between order placement and settlement introduce financial uncertainty that may not be worth it for an automaker operating on thin margins.
Branded optics add another layer. Tesla’s image is built on environmental credibility, and even a small dip in Bitcoin’s energy profile could spark backlash from investors and ESG-conscious customers. The company may prefer to err on the side of caution rather than face renewed criticism if its mining operations move back into fossil fuel-heavy regions.
Finally, operational integration cannot be ignored. To bring Bitcoin payments back online, Tesla would have to rebuild the wallet infrastructure, transaction pipelines, and conversion mechanisms. That requires engineering resources and internal approvals: steps that are far from trivial for a global manufacturer already balancing multiple product launches and software initiatives.
Taken together, these factors suggest that meeting the 51% renewable energy threshold is not enough on its own. For Musk, the test appears to be as much about trust, consistency and perception as it is about raw data. Until these align, Tesla’s checkout page will likely remain crypto-free.
What this means for adoption
From a narrative perspective, Musk’s renewed involvement has an impact. If Bitcoin can credibly stick to a cleaner energy mix and large commercial peers like Tesla start transacting again, it would solidify a more sustainable narrative for crypto.
Still, Tesla’s continued off-chain status, despite claims, suggests that Musk sees the promise as conditional, not automatic. The test is about optics, risk management and stories as well as simple statistics.
For now, Bitcoin’s claimed “51%+ sustainable” status provides a compelling rebuttal to critics, but until the cash registers return, it remains more of a symbolic victory than a commercial one.