Kerosene, diesel, and propane have traditionally been used in agricultural operations to power generators when grid connection was not available. However use of these fuels has problems:
cost of transporting fuel, volatility of fuel costs, fuel spillage, noisy generators, noxious fumes, and high maintenance needs. The disadvantages of using propane or bottled gas to heat water for pen cleaning or in crop processing applications, or to heat air for crop drying, are the cost of fuel and transportation, along with safety concerns.
For many agricultural needs, solar energy provides a good alternative. Modern, well-designed, simple-to-maintain, and cost-effective solar systems can provide energy that is needed when and where it is needed.
The introduction of solar PV in the late 1950s came through space applications. During the energy crisis in the 1970s, PV technology gained recognition as a source of power for non-space applications and found an application in remote powering, including rural settings. For agriculture, the sales of solar-PV stand-alone systems began in the 1980s. At the time, the most common agricultural applications included running motors, pumping water, charging vehicle batteries, and powering remote security lighting.
The primary agricultural applications for solar-PV electricity have been for battery charging (fence chargers, gate openers, and building lighting), and water pumping from remote wells, streams, or lakes (to provide water for domestic uses, livestock, and small-scale irrigation). Supplementing (or substituting) electricity from the grid has gained momentum over the last decade. Depending on the size of the system and the application required, PV systems for an agricultural operation can cost as little as a few hundred dollars to as much as thousands of dollars.
Today, distributed generation, backup in the case of utility grid outage, and net metering present further opportunities for grid-connected solar energy use in solar agricultural settings. Larger solar installations for solar agriculture have been developed; still, in agriculture solar energy generation has been small when compared to wind energy generation and to date has not surpassed 1Megawatt (MW). Small solar PV installations are below 10 kilowatt (kW), small commercial are 10kW-40kW, and large commercial PV installations range from 40kW-1MW.
There is upward trend and the persevering volatility in diesel and natural gas prices for the last decade. With a nationwide average of 6% of farm expenses relating directly to energy, solar has emerged as an alternative energy (solar agriculture) source that ensures predictability, independence, and even cost effectiveness for a number of agricultural applications. Potential is even higher for crop farming where energy expenses reach 9%. Energy expenses on the farm are also above average for greenhouse nurseries, floriculture, aquaculture, sheep, goat, and beef production.