Energy efficiency and renewable generation can reduce the energy cost and environmental impact of buildings. While both approaches are effective, the best results are achieved when they are used together. This applies for both homes and businesses.
The best strategy is to focus on energy efficiency first, reducing energy consumption as much as possible. Once this point has been reached, electricity needs can be met more easily with on-site renewable generation.
There are many energy efficiency measures available, and there are also many renewable generation technologies. The best results are achieved when these measures are selected based on the needs of each property.
Energy Efficiency Measures for Homes and Businesses
Energy efficiency measures are characterized by their variety, but some are useful in almost any project. In homes and commercial buildings, the most effective measures are those that focus on lighting, air conditioning and heating.
LED lighting offers energy savings that range from 30 to 90 percent, depending on the type of lamps being replaced. LED products also have a much longer service life, leading to less lamp replacements in the long run.
- For example, a 60-watt incandescent lamp that lasts 1,000 hours can be replaced with a 10-watt LED bulb that lasts 25,000 hours.
- The LED lamp consumes over 80% less energy, while lasting 25 times longer.
There are many options when upgrading to LED. Some LED lamps are designed to use the same sockets and power supplies as the existing lamps, which allows a simple replacement. Other LED products replace the existing fixtures completely; they are generally more expensive but also more efficient.
Heating and cooling systems account for over 50% of energy consumption in many homes and commercial buildings. Efficiency measures that target these systems can drastically reduce the energy consumption and environmental footprint of a property.
- Window-type air conditioners can be replaced with mini-split units. A modern unit with a SEER rating above 25 can achieve savings of over 70% when replacing a window air conditioner.
- The most efficient furnaces and boilers have an Annual Fuel Utilization Efficiency (AFUE) of over 95%, while older units are below 60%. In these cases, an upgrade can drastically reduce fuel consumption and emissions.
- Heat pumps have emerged as a viable alternative to combustion heaters, using only electricity and no fuels. Many models can switch to cooling mode, assuming the role of air conditioners, and consolidating two pieces of equipment into one system.
Before upgrading heating and cooling equipment, a building envelope inspection is recommended. Deficient insulation and air leaks reduce the performance of HVAC equipment, even if the new units have a very high efficiency. Energy consultants can detect building envelope issues with methods like thermal imaging and pressurization tests.
Using Renewable Energy Effectively
Renewable energy sources are also varied, but solar power has emerged as the most flexible and adaptable option. The number of solar panels can be specified according to the needs of each property: most homes can get good results with 20-30 panels, while large companies use thousands of them. Solar power systems also have minimal maintenance needs, and the leading brands offer a 10-year warranty against manufacturing defects.
Wind power, biomass power and small-scale hydropower are also viable if the building in question has the right site conditions.
- In windy sites, having a large wind turbine is better than having several small ones. Wind speeds are more stable high above the ground, and the cost per kilowatt is much less with a single large turbine.
- Biomass is a viable energy source for homes and businesses with access to sufficient amounts of organic waste.
- Small hydroelectric turbines can be deployed if a property has a creek or small river.
The combination of energy efficiency and renewable sources can minimize the energy costs and environmental footprint of a home or business. If a building can produce enough clean energy locally to fully meet its consumption, it becomes a net-zero energy building (NZEB).
About the writer:
Michael Tobias is the founder and principal of Chicago Engineers, an Inc 5000 Fastest Growing Company in America. He leads a team of 30+ mechanical, electrical, plumbing, and fire protection engineers from the company headquarters in New York City; and has led over 1,000 projects in Chicago, New York, New Jersey, Pennsylvania, Connecticut, Florida, Maryland and California, as well as Singapore and Malaysia.