Lesson 4 of 9 · about 17 minutes

Setbacks, Height, Noise and Glare Standards

You'll be able to

Read and apply a tiered setback table for solar, battery storage, wind and transmission
Compute a 'greater of' wind setback and the mailed notice radius for a tall structure
Estimate how far sound must travel to drop to a noise limit, and know the limits of that estimate
Say which standards are easy to defend and which invite a de facto ban argument

Most of the protection in a good energy ordinance comes from numbers in tables. Setbacks keep equipment away from homes, wells and canals. Height caps limit what can be seen for miles. Noise and flicker limits protect sleep. These standards are also where applicants push hardest, because each foot of setback is land they cannot use. The numbers below come from Jeff's energy facilities chapter, which he calibrated against stricter county codes around the country. Use them as a starting point and build the record for whatever numbers your county adopts.

Setbacks by tier

Measure from the outermost edge of any project component (panel, fence, inverter, battery container, turbine base) to the nearest point of the protected feature. Write that into the code; it heads off arguments about measuring from the center of a field.

Protected feature	Solar, Tier 2	Solar, Tier 3	Battery, Tier 2	Battery, Tier 3
Home on a non-participating parcel	500 ft	1,000 ft	500 ft	1,500 ft
Non-participating property line	100 ft	200 ft	150 ft	300 ft
Public road right-of-way	100 ft	200 ft	100 ft	200 ft
Active irrigation well	500 ft	1,500 ft	500 ft	1,500 ft
Canal, lateral or drain	200 ft	500 ft	200 ft	500 ft
School, church or community facility	1,000 ft	2,640 ft	1,000 ft	2,640 ft

Wind is different because the hazard grows with height: blade throw, ice throw, tower collapse, noise and flicker. Jeff's chapter uses "greater of" rules that combine a fixed distance with a height multiple.

Wind setback from	Tier 2	Tier 3
Non-participating home	Greater of 2,640 ft or 5 x total height	Greater of 5,280 ft or 7 x total height
Non-participating property line	2 x tip height	4 x tip height
Participating property line	1 x tip height (waivable in writing)	1.5 x tip height (reducible to 1 x by recorded waiver)
Public road	1.5 x total height	1.5 x total height
Canal or lateral	500 ft	750 ft

Transmission setbacks in the chapter scale with voltage: for Tier 3, 500 feet from a non-participating home for 69 to 114 kV lines, 1,000 feet for 115 to 229 kV, and a quarter mile for 230 kV and up.

Example: a wind project at the Owlcreek County line

Copperwind proposes turbines with a 600-foot tip height on private land near the BLM boundary. The nearest non-participating home is 4,800 feet from the nearest turbine. Tier 3.

Height multiple: 7 x 600 = 4,200 ft.
Fixed distance: 1 mile = 5,280 ft.
Greater of the two: 5,280 ft. The home is at 4,800 ft, 480 ft short. That turbine must move or go.
Non-participating property line: 4 x 600 = 2,400 ft.

Now notice. If the 600-foot height requires a height allowance through a special use permit, Idaho Code 67-6512(b) requires mailed notice to owners within at least three times the height for structures over 100 feet (3 x 600 = 1,800 ft) and within at least one mile for structures 400 feet or more in an unincorporated area, with the location and height stated in the notice. One mile governs. Jeff's package would go much further, county-wide notice for every Tier 2 and 3 project; lesson 9 covers the cost of that.

For scale: the approved Lava Ridge layout on BLM land limited turbines to 660 feet.

Height

The chapter caps solar panels at 15 feet above grade for every tier, and Tier 2 wind at 200 feet total height. Tier 3 wind has no absolute cap but requires photo simulations from every public road within 3 miles. A hard cap is the most defensible standard in this lesson. It is measurable, uniform and plainly connected to visual impact. A board that wants to keep tall turbines out of a valley can do it with a height cap in that district far more cleanly than with a character finding.

Noise

Jeff's limits, measured at the property line as Leq: Tier 2, 40 dBA day and 35 dBA night; Tier 3, 35 dBA day and 30 dBA night; plus a low-frequency limit for wind of 60 dBC (Tier 2) and 50 dBC (Tier 3) at the nearest non-participating home. Night runs 10 p.m. to 7 a.m. The code requires a pre-construction study and post-construction measurement.

Example: checking an inverter yard

Highline's noise study shows its central inverter yard at 45 dBA at 1,000 feet. The Tier 3 night limit is 30 dBA at the property line.

For a single point source in open air, level falls by 20 x log10 of the distance ratio, about 6 dB per doubling. (The big industrial projects lesson walks through the doubling table.)

To reach 35 dBA, a drop of 10 dB: distance ratio = 10^(10/20) = 3.16. 1,000 x 3.16 = about 3,160 ft.
To reach 30 dBA, a drop of 15 dB: ratio = 10^(15/20) = 5.62. 1,000 x 5.62 = about 5,620 ft.

So the inverter yard needs roughly a mile to its property line under the Tier 3 night limit, by distance alone. Real ground, air absorption and barriers often help; wind direction and temperature inversions sometimes hurt. That is why the code requires a professional study and follow-up measurement, not this sketch.

Here is where advocates need to be careful. A 30 dBA night limit at a property line is a very low number, and in a quiet place it may sit close to the existing nighttime background. An applicant will argue, with some force, that the standard is a ban dressed as a noise rule. The honest responses run like this. If the county intends a ban in that district, say so in the use table. If it intends to allow facilities under strict limits, set the measuring point at the nearest non-participating home, or set the limit relative to measured background (for example, no more than 5 dBA above the pre-construction nighttime background), which ties the number to evidence. Both versions are defensible. A limit written to be unmeetable while claiming otherwise is the weakest of the three.

Shadow flicker

The chapter limits flicker at occupied buildings on non-participating parcels to 30 hours a year and 30 minutes a day (Jeff's draft lists 20 hours and 20 minutes for Tier 2, which is stricter than Tier 3; a county should fix that inversion so the larger tier is never the looser one). Tier 3 requires automatic shutdown when a turbine would exceed the daily limit, with logs. Flicker is predictable from geometry, so modeling is routine and shutdown controls are a known technology.

Glare, screening and lighting

Glare: a glare analysis for Tier 2 and photo simulations for Tier 3, with anti-reflective panel coatings required. Add homes, roads and any airport approach as receptors.
Screening: a 30-foot native vegetation buffer for Tier 2 and 60 feet for Tier 3, with a five-year establishment guarantee.
Lighting: no uplighting; full-cutoff, downward, motion-activated security lights only.

Common mix-ups

Claim: State law fixes notice at 300 feet, so a county cannot send more. What the evidence shows: 300 feet is the floor in 67-6512(b). The commission may add any area "substantially impacted," and height-allowance permits carry larger mandatory radii.
Claim: Bigger setbacks always beat smaller ones in court. What the evidence shows: Courts look for a rational link to evidence in the record. A 1-mile wind setback backed by noise and flicker modeling is stronger than a larger number with no study behind it.
Claim: Solar farms are silent. What the evidence shows: Panels are, but inverters, transformers and battery cooling make steady sound. Ask for the equipment list and its sound data.

Reporting angle

Request the applicant's noise study, flicker model and glare study. Check the receptor list: is every home within 2 miles on it?
Compare the site plan's setback measurements to the code's measuring rule. Are distances taken from the fence, the nearest panel or the parcel center?
Ask which equipment the noise study modeled and whether the final equipment matches. Swaps after approval are common.
After construction, ask for the compliance measurement report the permit requires and the date it was filed.
Under Idaho Code 67-6535 the written decision must explain the standards applied and the facts relied on. Read it against the tables.

Research angle

Notice and conditions: Idaho Code 67-6512. Written decisions: 67-6535.
How decibels add and fall with distance: SoundStudio theory, decibels.
Wind technology and siting background: the wind lesson in the renewables course.
Enforceable condition wording: the conditions of approval lesson.

Check yourself

1. A wind turbine has a 600-foot tip height. The Tier 3 rule for non-participating homes is 1 mile or 7 times total height, whichever is greater. What is the setback?

2. Under Idaho Code 67-6512(b), when a special use permit is sought because of a height allowance for a structure 400 feet or taller in an unincorporated area, how far must mailed notice reach?

3. A point source measures 45 dBA at 1,000 feet. Ignoring air absorption and terrain, roughly how far until it falls to 35 dBA?

4. Why might a 30 dBA nighttime limit at the property line draw a 'de facto ban' argument?

5. Which standard is the most objective?

Terms in this lesson

Setback: The minimum distance between a facility component and a protected feature such as a home, property line, road, well or canal.
Participating parcel: Land whose owner has signed an agreement with the developer, such as a lease or easement; non-participating parcels have no agreement.
dBA: Decibels with A-weighting, which approximates how human ears hear different frequencies.
Leq: Equivalent continuous sound level: the steady level with the same energy as a fluctuating sound over a set period.
Shadow flicker: Moving shadows cast when turbine blades pass between the sun and a viewer, measured in hours per year and minutes per day.

Full glossary

Sources

Idaho Code 67-6512, Special use permits, conditions, and procedures (height notice, conditions) checked 2026-10
Idaho Code 67-6535, Approval or denial to be based upon express standards and in writing checked 2026-10
Wikipedia, Lava Ridge Wind Project (660-foot turbine height limit in approved layout) checked 2026-10