Ideas to fuel a sustainable built environment

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Retrocommissioning and Energy Efficiency BEFORE Renewables

Feb 29, 2012 5:00:00 AM

Renewable energy – wind and solar in particular – are all the rage these days. Companies are clamoring to be to be seen as “green” to feel good about their power sources and to market this image to the world. But what many don’t do first is the less glamorous and less visible step of reducing their need for energy by retrocommissioning and investing in energy efficiency. Why put in a large array of solar panels when a quarter of this load represents wasted building energy?

Wayne National Forest Solar Panel Construction

Put Energy Savings First

The surge in enthusiasm for renewable energy is useful in raising companies’ awareness about energy issues in general, but rather than starting with renewables, making them one of the last steps of a more comprehensive energy plan is key to realizing the most effective energy cost savings with the least costly capital investment. The hidden costs of an inefficient facility will eat up 10 – 35% of the utility cost of a commercial building. Outdoor lights that remain on during the day; indoor lights that remain on during the night; makeup fans, exhaust fans, pumps and air handlers that run around the clock; and water heaters set at excessive temperatures are all examples of concealed wasted energy. Attacking these types of items and establishing a clear picture of your energy needs will help inform your decisions on the size of the renewable infrastructure you’re excited to buy. It’s like purging your unnecessary belongings before you move to a new house instead of after you move (or never). There is a lot less baggage, you feel good about the things you’re hauling and you only pay for the moving service you really need. It’s the same idea for sizing your solar panel or wind turbine – the cost of reducing a building’s energy consumption is considerably less than the cost of solar arrays or wind turbines. Investing in energy efficiency first will enable the more costly wind or solar power to produce useful energy and supply a greater portion of a building’s operating costs.

Achieving Energy Savings

Retrocommissioning – commissioning of an existing building – is the process of taking a detailed look at the functionality of the building’s mechanical and electrical systems. A good retrocommissioning agent is also looking for efficiency opportunities. In retrocommissioning, engineers examine the air handlers and chilled water and hot water plants (are they piped correctly, are the valves working, are there opportunities for variable speed drives, do the operating schedules reflect the building occupancy), and the lighting (are lighting controls working correctly, are there opportunities for better controls, are lighting schedules accurate). Addressing the efficiency of the building envelope – windows, doors, walls and roof – is typically less cost-effective, but is also helpful in reducing energy consumption and improving occupant comfort.

Only when the building systems are functioning properly and most efficiently does it make sense to determine the building energy load and the size of wind or solar generation. Your dollars will go much further, your renewable systems will reflect your needs and you will still have the glory of the visible renewable energy source.


Written by Eveline Killian