Bitcoin’s seven-day network hashrate average climbed from roughly 926 EH/s to 975 EH/s during September, a gain of about 49 EH/s in one month. Hashrate Index’s October 9 monthly lookback ties that rebound to the end of Texas summer curtailment as ERCOT’s final Four Coincident Peak, or 4CP, period passed on September 12.

The move is large enough to matter. A 49 EH/s increase equals roughly 5.3% growth from September’s starting seven-day average. It also helps explain why Bitcoin’s network pushed back toward the 1 ZH/s threshold so quickly after the summer slowdown.

The Network Added About 5.3% in One Month

Moving from 926 EH/s to 975 EH/s is a gain of approximately 5.29%. That is a large monthly move for a network already operating near one zettahash per second.

It does not mean 49 EH/s of brand-new ASICs were installed during September. Some of the increase can come from machines that were already deployed but curtailed, underclocked, offline for maintenance, or temporarily removed from production.

BitcoinVersus recently covered an estimate that roughly 235 EH/s of Bitcoin mining capacity was sitting idle. September’s rebound is consistent with part of that installed capacity returning to the network when operating conditions improved.

Texas 4CP Season Ended in September

ERCOT’s Four Coincident Peak framework tracks peak demand during June, July, August and September. Large electricity users in Texas have a strong incentive to reduce load when they believe one of those system peaks may occur because those intervals can affect future transmission charges.

ERCOT’s official 4CP page confirms that the program calculations cover those four summer months. For industrial Bitcoin miners, that creates a recurring reason to curtail machines during high-load summer periods even when the ASICs themselves are fully functional.

Hashrate Index reports that the final 4CP peak passed on September 12 and that previously curtailed Texas hashrate returned as the season closed. September blocks averaged about 9 minutes 23 seconds, the fastest monthly average since February, with 23 of 30 days below Bitcoin’s 10-minute target.

For Texas bitcoin miners: how do you manage ERCOT 4CP risk and curtailment?
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Forty-Nine EH/s Can Represent Nearly 1 GW of ASIC Load

Hashrate can be translated into an approximate electrical load if we assume a fleet efficiency. At 15 J/TH, 49 EH/s corresponds to about 735 MW of ASIC-level power. At 17.5 J/TH, it is about 858 MW. At 20 J/TH, it approaches 980 MW.

Those calculations are not proof that 735–980 MW of Texas mining load came back online in September. The 49 EH/s increase was global, and the network estimate can also move with block luck. The calculation only shows the physical scale of compute represented by a 49 EH/s change.

It also explains why mining is useful as flexible grid load. Hundreds of megawatts of ASIC demand can be reduced and restored much faster than many traditional industrial processes. ERCOT formally created a voluntary curtailment program for large flexible loads such as Bitcoin mining facilities to support grid reliability during high-demand periods.

Difficulty Took Back Most of Bitcoin’s Price Gain

The hashrate comeback did not translate into an equally large improvement in miner economics. Hashrate Index says Bitcoin rose about 7.3% from the beginning to the end of September, but USD hashprice increased only about 1.8% to $39.92 per PH/s/day.

The reason was difficulty. Bitcoin posted two upward adjustments during the month—approximately +1.31% on September 5 and +4.16% on September 19—for a combined monthly increase of about 5.52%.

That is the feedback loop miners face whenever curtailed or idle machines return. More hashrate speeds up block production, the protocol raises difficulty, and revenue per unit of hashrate gets compressed unless Bitcoin price or transaction fees rise enough to offset it. BitcoinVersus recently showed the same dynamic in its miner-revenue recovery analysis.

The Forward Market Expected 1 ZH/s Later Than the Network Did

Luxor’s forward market adds another useful signal. Hashrate Index says September’s forward curve implied the network would cross 1,029 EH/s in January 2027. But the seven-day network average had already reached about 999 EH/s on October 8.

That means the physical network was approaching the one-zettahash milestone faster than the September forward curve had implied. If the current comeback persists, the market may have underestimated how quickly curtailed or idle mining capacity could return.

Watch How Miners Manage Power and Curtailment

Luxor’s Energy platform demonstration below shows how industrial miners combine real-time electricity pricing, site load, mining revenue and automated dispatch signals when deciding whether to keep ASICs running or curtail them.

What the Data Shows

• Bitcoin’s seven-day hashrate average rose from about 926 EH/s to 975 EH/s during September.
• The 49 EH/s gain equals roughly 5.3% monthly growth.
• ERCOT’s final 4CP peak passed in September, allowing curtailed Texas mining load to return.
• At 15–20 J/TH, 49 EH/s is physically equivalent to roughly 735–980 MW of ASIC load, although the global hashrate increase cannot all be attributed to Texas.
• Difficulty rose about 5.52% during September, absorbing most of Bitcoin’s 7.3% price gain from the perspective of unit mining revenue.

The important inference is that Bitcoin’s summer hashrate slowdown did not necessarily represent permanently lost mining capacity. A meaningful amount of compute was waiting behind power-market economics. Once the Texas summer incentive to curtail faded, the network recovered quickly—and difficulty immediately began pricing that returning capacity back into mining economics.