🏛️ Issues and Advocacy Training
Courses › Southern Idaho Energy Issues

Lesson 7 of 8 · about 16 minutes

The Big Solar Question

You'll be able to

  • Say what the record does and does not show about a 15,009-acre solar proposal in southern Idaho
  • List the largest verified southern Idaho solar proposals with acreage, capacity and status
  • Use acres per megawatt to sanity-check a reported project size
  • Compute a solar project's production tax and compare a decommissioning bond with published cost estimates

This course went looking for a proposed 15,009-acre solar project in southern Idaho and did not find one. The search covered BLM announcements, county agendas and staff reports in the Magic Valley and Elmore County, Idaho PUC filings, project trackers and Jeff Pierson's own files. That doesn't prove no such proposal exists. Early-stage BLM applications and private land deals can sit out of public view for a long time. It does mean the number should not be repeated as fact until someone can point to the filing.

Here is what the record does show, and the tools to check a big number when it surfaces.

The largest verified proposals

ProjectWhereAcresCapacityStatus as of October 2026
Snake River Energy Solar (Arevia Power)BLM land in Gooding, Lincoln and a neighboring Magic Valley county, north of Twin FallsAbout 4,609400 MW, sharing a 550 MW battery facility with the Taurus Wind proposalBLM public forum Jan. 28, 2025; linked to the Rhea Data center proposal in September 2026 reporting; no decision found
Soles Rest SolarWestern Elmore County, seven leased private parcels along I-84About 981Up to 149 MWac (about 195 MWdc)Staff recommended approval with 39 conditions; workshop July 23, 2026
Crimson Orchard Solar and storage (Clenera)Elmore County, on J.R. Simplot Company landNot stated in the staff report100 MWac solar plus 100 MWac batteryP&Z hearing March 13, 2025; listed as in development for April 2027 by Cleanview
Blacks Creek (rPlus Energies)Ada County, south of BoiseNot verified400 MWacListed by Cleanview as in development, expected online June 2027
A floated Lincoln County projectLincoln CountyAbout 8,000 (as discussed locally)Not statedJeff Pierson's Feeding the Beast No. 5 analyzes it as a pitch; no application found

The Snake River Energy Solar project is the biggest by acreage that this course could confirm, and it's worth watching for a second reason: September 2026 reporting tied it to the Rhea Data center proposal south of Boise. Solar on BLM ground north of Twin Falls feeding a gas-and-solar data center south of Boise is the kind of link the next round of filings should explain.

Checking a big number

Solar takes land in a fairly predictable ratio, so acreage tells you roughly how big a project is, and the reverse.

Example: what would 15,009 acres mean?

  • Soles Rest ratio: 981 acres / 149 MW = about 6.6 acres per MW.
  • Snake River Energy Solar ratio: 4,609 acres / 400 MW = about 11.5 acres per MW.
  • 15,009 acres at 6.6 acres per MW: 15,009 / 6.6 = about 2,274 MW.
  • 15,009 acres at 11.5 acres per MW: 15,009 / 11.5 = about 1,305 MW.

A 1,300 to 2,300 MW solar farm would be several times larger than anything built or proposed in Idaho that this course found. Idaho Power's entire 2025 IRP preferred portfolio added 1,445 MW of solar over 20 years. A project that size would need an interconnection request, likely a BLM right-of-way or many private leases, and a buyer. Ask for any one of those and you'll know fast whether the number is real. If the figure turns out to describe a study area or a lease block rather than a project footprint, that's a common source of inflated acreages.

What the county gets: the tax side

Idaho does not tax a solar farm's equipment like a house or a factory. Idaho Code 63-602JJ exempts property used to generate electricity by solar, wind or geothermal producers who pay the production tax. Idaho Code 63-3502B sets that tax at 3.5 percent of gross solar energy earnings (3 percent for wind and geothermal). The solar money reduces the property tax levied to fund a district's budget, and it does not count as property tax revenue for the budget-growth limits in Idaho Code 63-802.

Example: production tax on a 149 MW project

These inputs are assumptions for illustration; the real ones are in the power purchase agreement.

  • Assumed capacity factor 28 percent: 149 MW x 0.28 x 8,760 hours = 365,467 MWh a year.
  • Assumed price $40 per MWh: 365,467 x $40 = $14,618,680 in gross earnings.
  • Tax at 3.5 percent: $14,618,680 x 0.035 = about $511,654 a year.

The number moves with the price and the weather, and it ends when the project stops selling power. Supporters point out that this is far more than grazing or dryland farming pays in taxes on the same ground. The "Tax-Base Mirage" section of Jeff Pierson's Feeding the Beast No. 5 argues the revenue is a 30-year pulse, and that the long-term costs of cleanup and land recovery are left out of the pitch. Both statements can be checked with the same arithmetic.

The bond that outlasts the panels

Soles Rest is useful because its staff report puts real numbers on decommissioning.

Example: is the Soles Rest bond enough?

  • Applicant's decommissioning estimate: $9,485,019.
  • Per acre: $9,485,019 / 981 = about $9,669 per acre.
  • Initial bond at construction, 50 percent: $4,742,510, or about $4,834 per acre.
  • Rises to 100 percent at year 10 and 125 percent ($11,856,274) at year 15; the estimate is updated every five years.
  • Comparison: Feeding the Beast No. 5 says published estimates run around $15,000 an acre. At that rate: 981 x $15,000 = $14,715,000.

So the starting bond covers about a third of that rough published figure, $4,742,510 / $14,715,000 = 0.32, and the full 125 percent bond at year 15 still lands below it. The applicant will argue its estimate nets out salvage value for steel, aluminum and copper, which published estimates may not. The county's question is who carries the gap in the first ten years if the owner fails, and whether the five-year updates use net or gross figures.

Common mix-ups

  • Claim: A 15,009-acre solar farm is planned for southern Idaho. What the evidence shows: This course found no filing matching that figure as of October 2026. The largest verified proposal is about 4,609 acres.
  • Claim: Solar farms pay property tax on their panels. What the evidence shows: The generating equipment is exempt; the producer pays 3.5 percent of gross solar earnings instead.
  • Claim: A decommissioning bond always covers cleanup. What the evidence shows: Bond schedules often start partial. Soles Rest starts at 50 percent of the applicant's own estimate.

Reporting angle

  • When anyone cites the 15,009-acre figure, ask for the application number, the landowner or BLM serial number, and the interconnection queue position.
  • Request Idaho Power's public interconnection queue and filter for solar requests over 300 MW in the Magic Valley.
  • For each county CUP, request the decommissioning plan, cost estimate and bond schedule under Idaho Code 74-102.
  • Ask whether the decommissioning estimate is gross or net of salvage, and who audits the five-year updates.
  • File a FOIA request (5 U.S.C. 552) with the BLM for the Snake River Energy Solar plan of development and any updates since January 2025.

Research angle

Check yourself

1. Soles Rest Solar in Elmore County is up to 149 MW on about 981 acres. About how many acres per megawatt is that?

2. Under Idaho Code 63-3502B, what tax does a solar producer pay in place of property tax on its generating equipment?

3. What is the largest solar acreage this course could verify for a single proposed project in the Magic Valley?

4. Soles Rest's decommissioning estimate is $9,485,019. Its bond starts at 50 percent at construction. How much is the starting bond, and when does it reach 100 percent?

5. At the acreage ratios seen in southern Idaho proposals, roughly how many megawatts would a 15,009-acre solar project be?

Terms in this lesson

MWac and MWdc
Solar capacity measured at the inverter output (AC) or at the panels (DC); the DC figure is larger.
Capacity factor
Actual energy produced divided by what the plant would make running at full rating all year.
Decommissioning bond
Money or a surety guaranteed up front so a project can be removed and the land restored if the owner fails to do it.
Large generator interconnection agreement (LGIA)
The contract with the utility setting the terms and upgrades for connecting a large generator to the grid.
Production tax (gross earnings tax)
A tax on a generator's earnings from selling power, paid in place of property tax on its equipment.

Full glossary

Sources