Solar energy vs. shade - Solar, Wind and Land: Conflicts in Renewable Energy Development - page 100

valued use of the space than occupying that space with buildings or trees.
The challenge for policymakers is to craft workable laws that actually
create those incentives for landowners in their jurisdictions. This chapter
recounts the history of laws involving sunlight and analyzes several modern
solar access policies developed after the advent of solar energy technologies.
The chapter ultimately advocates a particular policy approach designed to
promote optimal use of the scarce airspace resources implicated in disputes
over solar access.
Solar access laws prior to the solar energy era
Although disputes over solar panel shading are relatively new, conflicts over
access to sunlight have been around for centuries. A brief recounting of the
history of laws relating to sunlight helps to put modern solar access issues
into context. 4
Direct sunlight has played a prominent role in indoor lighting throughout
most of human history. Until the twentieth century, illumination from
candles, lamps, and other fire-lit devices was the only alternative to natural
sunlight. Because daytime sunlight was free of cost and created no smoke
or fire risk, it was an important light source in many buildings. It is easy to
understand the frustration that landowners in such settings must have felt
when new buildings or walls erected on nearby parcels suddenly shaded the
windows of their dwellings.
The ancient Romans recognized the tremendous importance of sunlight
access in buildings and thus enacted laws to protect it. According to one
pair of scholars, civil laws in ancient Rome required that builders either
“leave [...] neighbors a minimum or reasonable amount of daylight” or
obtain from neighbors a “servitude” allowing for a greater amount of
light obstruction. 5 Although such laws surely offered some protection to
landowners, ambiguity regarding what constituted a reasonable minimum
quantity of daylight may have made such laws difficult to enforce.
The doctrine of ancient lights
Rights to sunlight access also enjoyed robust protections under English
common law. Under the English “doctrine of ancient lights,” a landowner
who benefited from uninterrupted sunlight use on a parcel for a full
prescriptive period could thereby obtain the equivalent of a perpetual
easement protecting that sunlight access. 6 Dating back to at least 1610, this
legal doctrine has existed in one form or another in the United Kingdom for
over four centuries. 7 By the year 1832, 20 years was the clearly-established
prescriptive period of uninterrupted use required to obtain rights to light
under the rule. 8
Although the doctrine of ancient lights still existed in the United
Kingdom as of 2013, 9 few western courts outside that country ever