Energy management for residential buildings
Raghav Kapur

The International Energy Association predicts that electricity usage for residential appliances would grow by 12 per cent between 2000 and 2010, eventually reaching 25 per cent by 2020. This means strict measures need to be undertaken in residences as well buildings not just to conserve energy but also help protect the environment. Let’s look at few ways that can be done:

Energy Baseline: Create an energy baseline that outlines the current energy performance and helps you define a new energy strategy for further usage. A baseline data is collected from building management system, energy invoices and the utility provider’s report; this includes the usage based on peak and non-peak hours and tariff charges levied accordingly on it. This should be a conclusive based on last 12 months to keep a track of energy variations as per the seasons. This not only helps setup a platform for where your average consumption stands through the year and sets a target goal, but will also tell you when the consumption pattern is pinching you the most, for instance in the summer you may notice the consumption spiking which indicates the first thing to tackle might be optimising air conditioning units.

Energy Audit: Energy audits are the first step towards optimising energy consumption. There are several companies that carry out a day long energy audit in homes or office, and suggest cost effective ways to reduce your consumption by upto 15 per cent per month. They use specialised tools and skills to evaluate your building and recommend the most cost-effective measures to improve its comfort and efficiency, they also provide independent verification of the electric system’s quality. Based on the energy audit and the baseline you can then set up performance targets for the building’s energy usage, these targets will also include the resident’s expectations and the budget constraints. Some of the solutions may be much simpler than you think, for instance just the placement of you air conditioning units to complete of full flow cycle could help save on consumption without any added costs.

HVAC Management: Heating, ventilation and air conditioning (HVAC) is the principal energy consumer in multi-unit residential buildings, and often consumes up to a third of total electricity usage. Few ways the HVAC management can be done is –

Review the HVAC settings regularly through BMS

Ensure the regular maintenance of the equipment for it to operate as per its complete potential

Install variable speed drives on pumps and fans

Set operating hours and routine – the HVAC can be turned off when not in use

Light Management: Lighting in common areas is where significant cost saving can be done. The most overlooked way aspect of reduce energy consumption through lighting is the lack of proper planning while designing a space. Its commonly noticed that most homes or offices have unnecessarily increased the number of lights that are actually needed to illuminate a space. This could also be because designers/architects often have a margin baked into each light that is installed, but spending a little bit of time reviewing the lighting layouts to optimise consumption would go a long way. The second major aspect is the use of efficient lights that reduce the heat effect which in turn reduces the air condition costs, this is besides the fact that they last longer and require less maintenance. Few others way to ensure effective light usage are –

Replace CFL’s with LEDs as they are far more energy efficient than incandescent or fluorescent lights, which emit light in a much wider band of wavelengths

Manual timers can be used for controlling objects such as lamps or light strings whereas in-wall programmable digital timers can be used to automate indoor or outdoor lighting

Remove light bulbs in areas they are over exposed where high luminance is not essential

Rewiring and Insulation: Electrical rewiring is the process whereby old, hazardous or non-compliant electrical equipment such as cables, distribution boards, fittings, are replaced for better performance, check the areas that need rewiring and make the change at the earliest. Insulation acts as a barrier to heat flow and is essential for keeping the building/home warm in winter and cool in summer, it also improves the indoor air quality and the utility bills.

Renewable Energy: These days’ photovoltaic panels are being incorporated into the construction of new buildings as a principal or secondary source of electrical power, these panels are cost effective when it comes to multi-unit residences. One of the best ways to conserve and to have cleaner utilisation of energy can also be done by installing solar panels for overall energy grid or even just for the water heater.

Use of Technology: Today technology has spread into almost all verticals of daily life, and home/office systems and equipment are no exception. Energy consumption patterns can be significantly reduced by implementing technology into the electrical equipment in a space. For instance the use of motion detectors in lighting could easily help reduce your lighting consumption while providing no loss in comfort, similarly with air conditioners that work via a thermostat to maintain an ambient temperature rather than staying operational for hours together.

Monitor & Report: Once these strategies are established, create a process that will help collect, analyse and record the energy consumption. Once the process is set, measure the consumption with the baseline to assess energy performance trends, the efficiency of the initiatives applied and also measure future opportunities to improve.

(The writer is city head – Bangalore, SILA)