Public miner audit · Oct 12, 2026 · 5 min read
TeraWulf in the first half of 2026: 4.8¢ per kWh all-in, and $45,400 per bitcoin
TeraWulf mined 347 BTC at Lake Mariner in the first half of 2026. Its power cost 7.6¢ per kWh before demand-response payments and 2.4¢ after them. With every other site cost added, the all-in rate was 4.8¢ per kWh, or $45,400 per bitcoin.
TL;DR
- 347 BTC mined in the first half of 2026: 168 in the first quarter, 179 in the second.
- Demand-response payments are the story. Power cost 7.6¢ per kWh before them and 2.4¢ after them. In the first quarter, the payments were larger than the power bill.
- All-in, the sites ran at 4.8¢ per kWh, or $45,400 per bitcoin, against $74,400 of revenue per bitcoin mined.
- The loaded rate (11.7¢) carries a share of company overhead. That overhead mostly serves TeraWulf's data-centre business, so it deserves less weight here.
- Mining is the smaller business now. Leasing to AI and HPC customers brought in 71% of revenue in the second quarter.
What they reported
TeraWulf is a US company that files quarterly reports with the SEC. This piece covers the two quarters to 30 June 2026, taken from its first-quarter 10-Q and second-quarter 10-Q, with the 2025 10-K for context. All of its mining is at the Lake Mariner campus in Barker, New York, which buys its power on the NYISO Zone A grid.
The business is changing fast. TeraWulf reports two segments, Digital Asset Mining and HPC Leasing. It leases data-centre space to AI and HPC customers at Lake Mariner and is building more campuses in Kentucky, Maryland and New York. HPC leasing was 62% of revenue in the first quarter and 71% in the second. Miner buildings are being turned into data halls. Operational hashrate went from 9.3 EH/s at the end of 2025 to 7.9 EH/s at 31 March and 5.6 EH/s at 30 June. That leaves about 1 bitcoin mined per day, from 145 MW of mining capacity. The fleet is mostly Bitmain S21 Pro and S19j XP, at an average of 17.2 J/TH in March and 17.6 J/TH in June.
The power bill, before and after demand response
New York pays large power users to switch off when the grid is stretched. TeraWulf counts these demand-response payments as a reduction in its cost of revenue. So the power figure it reports is net: the bill minus the payments.
In the first quarter, a long cold spell in the Northeast kept the miners off for much of the time. The payments came to $14.1 million and the gross power bill was about $14.0 million, so net power was minus $90,000. The company reports its realised power price for the quarter as $(0.001) per kWh, which matches our minus 0.05¢. In the second quarter the payments fell to $2.8 million, and net power was $7.9 million: 4.9¢ per kWh, against the company's own $0.049.
Across the half, the gross rate was 7.6¢ per kWh and the net rate 2.4¢. The difference is real money the company received, but it is paid for not mining, and it depends on weather and grid conditions in each quarter. Both are shown below. TeraWulf reports the MWh its mining used, so none of these rates rely on an estimate.
| Period | Gross power | Demand response | Net power | MWh used | Gross ¢/kWh | Net ¢/kWh | Company's figure |
|---|---|---|---|---|---|---|---|
| Q1 2026 | $14.0M | $14.1M | -$0.09M | 163,747 | 8.6¢ | -0.05¢ | $(0.001) per kWh |
| Q2 2026 | $10.7M | $2.8M | $7.9M | 162,369 | 6.6¢ | 4.9¢ | $0.049 per kWh |
| H1 2026 | $24.8M | $16.9M | $7.9M | 326,116 | 7.6¢ | 2.4¢ | $0.024 per kWh |
Everything else it takes to run the sites
Mining's other direct costs are its segment operating expenses (miner repairs, site labour, rent on the ground lease) plus a small line of non-energy utilities: $2.9 million in the first quarter and $5.0 million in the second. With them, the all-in rate was 1.7¢ per kWh in the first quarter, 8.0¢ in the second and 4.8¢ across the half. That is the figure to compare with an all-in hosting rate.
The loaded rate also adds a share of company overhead. We allocate cash SG&A (SG&A minus stock-based pay) by mining's share of revenue. At TeraWulf this is a weak measure. Company SG&A was about $127 million in each quarter, built mostly around the data-centre build-out, while mining brought in about $13 million a quarter. Mining's share comes to $10.1 million and $12.3 million of cash SG&A, giving loaded rates of 7.9¢ and 15.6¢ (11.7¢ for the half). The second-quarter figure includes a $14.4 million gift to the company's charitable foundation paid in shares, which this method counts as cash. Read the loaded rate as an upper bound.
| Period | Net power | Other direct costs | All-in | Cash SG&A allocated | Stock-based pay allocated |
|---|---|---|---|---|---|
| Q1 2026 | -$0.09M | $2.9M | $2.8M | $10.1M | $38.7M |
| Q2 2026 | $7.9M | $5.0M | $12.9M | $12.3M | $24.1M |
| H1 2026 | $7.9M | $7.9M | $15.7M | $22.4M | $62.8M |
What a bitcoin cost them
Per bitcoin, power came to $22,600 over the half and the all-in cost to $45,400, against $74,400 of revenue per bitcoin mined. TeraWulf states its own energy cost as $44,402 per bitcoin for the second quarter and $22,646 for the half, the same as ours. Its "cost to mine one bitcoin" ($44,547 in the second quarter) adds only non-energy utilities, which is why ours, with repairs, labour and rent, is higher.
The two quarters differ a lot. In the first, demand response made power free and the all-in cost was $16,700 per bitcoin. In the second, it was $72,300, about the same as the $71,700 each bitcoin was booked at.
| Period | Bitcoin mined | Power ¢/kWh | All-in ¢/kWh | Loaded ¢/kWh | Power $/BTC | All-in $/BTC | Loaded $/BTC | Revenue $/BTC |
|---|---|---|---|---|---|---|---|---|
| Q1 2026 | 168 | -0.05¢ | 1.7¢ | 7.9¢ | -$500 | $16,700 | $76,600 | $77,300 |
| Q2 2026 | 179 | 4.9¢ | 8.0¢ | 15.6¢ | $44,400 | $72,300 | $141,200 | $71,700 |
| H1 2026 | 347 | 2.4¢ | 4.8¢ | 11.7¢ | $22,600 | $45,400 | $109,900 | $74,400 |
The hardware
We keep machines out of cost per bitcoin. A miner is the roof over the operation, replaced every few years out of what it earns, and not part of what each bitcoin costs to make. It is shown here in full so nothing is hidden.
TeraWulf gives the depreciation of its miner fleet per bitcoin: $79,845 in the first quarter and $52,939 in the second. Multiplied out, that is $13.4 million and $9.5 million. Its six-month figure ($68,305 per bitcoin) gives $23.7 million for the half, $0.8 million more than the two quarters added together. Much of it is accelerated depreciation on miner buildings that are closing for HPC use. The first quarter also had an $8.9 million impairment for a mining facility that was shut down. Spending on new plant was $1.38 billion in the half, almost all of it for data centres, and no miner purchases were disclosed.
| Period | Miner depreciation | All company depreciation | Mining impairments | Mining capex |
|---|---|---|---|---|
| Q1 2026 | $13.4M | $28.5M | $8.9M | Not separable |
| Q2 2026 | $9.5M | $21.2M | $0 | Not separable |
| H1 2026 | $22.9M | $49.7M | $8.9M | Not separable |
What it means
Hosting at Firsthand's sites runs from 3.9¢ to 6.5¢ per kWh all-in, on our sites page. TeraWulf's all-in rate for the first half of 2026 was 4.8¢, made up of 7.6¢ of gross power, 5.2¢ back from demand response, and 2.4¢ of other site costs. It was 1.7¢ in a cold first quarter and 8.0¢ in the second, and the 347 BTC it mined came from a fleet that is shrinking as the campus moves to HPC.
Mining output depends on bitcoin's price, difficulty and uptime, and isn't guaranteed.
This is our analysis of the company's public filings, not an audit in the accounting sense.
Method and sources
Bitcoin mined, mining revenue, net power cost, MWh used and demand-response payments come from the "Average Cost of Bitcoin Mined" table, the segment note and the curtailment-credits note in each 10-Q. Gross power is net power plus the payments. MWh are reported by the company, so nothing is estimated. Other direct costs are the mining segment's operating expenses plus the non-energy utilities the company lists. SG&A and stock-based pay are company totals, allocated to mining by its share of revenue.
One figure does not reconcile. The second-quarter 10-Q gives gross power of $11.2 million and payments of $2.8 million, which would mean $8.4 million net. The reported net mining energy expense is $7.948 million. We use the reported net figure and payments, so our second-quarter gross is $10.7 million (6.6¢). On the company's $11.2 million it would be 6.9¢. The first quarter does reconcile.
Revenue split, depreciation and stock-based pay come from the income statements, cash-flow statements and the earnings releases (Q4 2025, Q1 2026, Q2 2026). TeraWulf discloses only period-end hashrate, not an average for the quarter.
Sources and further reading
- TeraWulf Form 10-K for 2025 — TeraWulf, 2026-02-27
- TeraWulf fourth quarter and full year 2025 results (8-K, Ex. 99.1) — TeraWulf, 2026-02-26
- TeraWulf Form 10-Q, first quarter 2026 — TeraWulf, 2026-05-08
- TeraWulf first quarter 2026 results (8-K, Ex. 99.1) — TeraWulf, 2026-05-08
- TeraWulf Form 10-Q, second quarter 2026 — TeraWulf, 2026-08-05
- TeraWulf second quarter 2026 results (8-K, Ex. 99.1) — TeraWulf, 2026-08-05
Disclosure
Firsthand Bitcoin sells and hosts mining hardware. This is our analysis of the company's public filings, not an audit in the accounting sense, and it is not investment advice. Every reported figure links to the filing it comes from; figures we estimated are labelled, with their inputs. No company paid for or reviewed this page. Corrections are published with the date they were made.