Getting started with renewable energy article in Home Power Magazine gives a straightforward advice about professional load analysis and site survey when starting with renewable energy.
The first step in renewable energy system planning is to determine how much energy is needed to be made:
- If the site is off grid, the stand-alone systems must provide all the site’s required electricity with renewable energy sources or a backup engine generator. This is when energy efficiency and conservation becomes critical. For this reason, most renewable energy consultants will ask for a detailed load profile. These systems also need to be accounted for seasonal energy availability. For example, more energy will be used in the summer because the house is for vacation use or pumps a lot of water for irrigation. In a year-round home, the critical energy time may be winter, when more lights and other loads are used.
- On grid sites doesn't require accommodating the complete load. Systems can cover as little as 10% to 50%, or even over 100% of home’s electrical use. Utility detects the imbalance and supplies only what is demanded from the user. Any extra energy produced will go to the grids, which will buildup KWH credits that can be used when system’s output is lower.
When determining energy requirements, most dealers will roughly calculate what size of system is needed and give a ballpark cost figure. Then the installing dealer or RE consultant will visit the site and assess what RE resources are available on the property. When planning the system, everyone who will be using it should know how it was planned, how it works, and what he or she can do to make it run well.
For solar energy, site surveyor will evaluate the property with a solar site selector tool. It helps determine which locations the property or roof are shade free. This will show the best location for PV array or solar water collectors. PV arrays can be put hundreds of feet away from home, but solar hot water systems need to be much closer because long pipes become costly and incurs high heat losses.
If the property has a potential wind energy site, wind turbine might be a great asset. However, wind turbine requires regular maintenance and poorly cared components can become hazards. Surveyor will determine if adequate room exists for a tilt-up tower, or freestanding tower is necessary. Freestanding towers have smallest footprint, and may be the only appropriate tower for a small lot.
Micro hydroelectric systems can be one of the most cost effective but sometime hard to implement because local, state, and federal authorities can have jurisdiction over the activity, unless water resource is completely privately owned. Hydroelectric works well with solar or wind energy sources since water still flows when there is no sun or wind.
Hybrid systems are best for off grid system because one source can backup another source and vice versa. However, hybrid capability is less important on grid-tied systems which use utility grid for backup. Battery-less grid-tied systems are often the most cost-effective, environmentally friendly, and easy to operate systems available.
Source: Home Power Magazine