Since buildings consume almost 29% of all energy consumed, investing in net-zero energy systems for buildings is an idea whose time has come. A Net Zero Energy Building is highly energy efficient and produces at least as much energy over the course of a year as it consumes. The SunCarrier Omega Net Zero Energy Building (NZEB), is an example of how organizations that can, to go beyond adopting the best in energy conservation technologies, and augmenting the energy supply by implementing 'green' energy systems that leverage nature's abundance of solar energy.
The SOPL NZEB evolved as a multi-act play:
Act One: Deployment of a renewable energy generator in the form of Solar PV system. The SunCarrier SC 260 was chosen since it was one of the largest sun-tracking solar PV systems worldwide, with a designed energy yield that was 35-40% higher than that of similarly rated static systems. Its large format, and its ability to track the sun, has made it a beacon for the eco-inquisitive and eco-concious from all walks of life. It now acts as a great motivator for those desirous of adopting sustainable energy policies for their own residential or commercial operations.
SunCarrier SC 260 at SunCarrier Omega NZEB site
Act Two: Incorporate demand-side energy efficiencies. The SunCarrier Omega NZEB design incorporated daylighting for high utilization of natural lighting; LED lighting and occupancy monitoring sensors. The air conditioning system chosen was one with ozone friendly refrigerant and carbon dioxide monitoring sensor system and low noise inverters. Water harvesting system, controlled water discharge toilets, and sewage treatment with zero discharge ensured efficient usage of water. The furniture chosen, too, was 95% recyclable.
Act Three: Integration of a large capacity energy storage system, the Cellcube FB 10-100. In addition to its ability to store upto 100 kWh of energy per unit, it also functions as an effective energy management system. Excess energy produced during the day by the SC 260 is stored in the Cellcube, which in turn supplies energy during the night hours, and during monsson days when the sun does not shine.
Cellcube FB 10-100 at SOPL NZEB site
Based upon the sizing for the SunCarrier Omega energy plan, the system was configured with 2 units of SunCarrier SC 260, with an overall rating of 67 kWp, for a planned yield of over 130,000 kWh per annum. 3 units of Cellcube FB 10-100, each with a maximum power rating of 15 kW, and a storage capacity of 100 kWh, were configured. 1 SMA Multi-cluster box completed the configuration.
SunCarrier Omega NZEB schematic
The system described above has a design life of 25 years. The SunCarrier SC 260 require minimal maintenance in terms of periodic cleaning the dust off the PV module surfaces. Since PV efficiencies are improving rapidly, periodic replacement to newer and more efficient modules is desirable, though not essential. The PLC controls and monitoring systems incorporated both in the SunCarrier SC 260 and the Cellcube FB 10-100 allow remote monitoring of critical performance parameters and take the rarely required preventive actions to ensure smooth functioning of the system. The systems are highly eco-friendly in that they are over 95% recyclable, emit no harmful gases or effluents, and there are no heavy metals to dispose off.
Act Four: Extension of its energy generation capacity in keeping with the anticipated growth in occupancy of the building. To support its growth, and still maintain its NZEB status, SunCarrier Omega has planned to integrate small Wind Turbines, the WindCarrier, in the energy mix. WindCarrier is a gearless, vertical axis wind turbine, based on the Darrieus principle, with a power rating of 10 kW. WindCarriers are highly efficient, and startup even at low wind speeds. With a hub height of 10 m and the ability to harness wind power regardless of wind direction, the Windcarrier may be deployed in urban environments to supply wind energy for private and commercial households, single family homes, farms, administrative and corporate buildings, and industrial plants.
Windcarrier proposed at SunCarrier Omega NZEB site
SunCarrier Omega NZEB has helped inform a large community of students, industrialists, politicians, bureaucrats, engineers, architects and other citizens about the said technolgies. That Net Zero Site Energy NZEB is easy to implement, manage, and monitor, and has few external dependencies. Sustainability is a cooperative endevour that succeeds best when adopted by as many stakeholders as possible. The visual impact of a Net Zero Site Energy NZEB, with its sun-tracking solar PV generators and large energy storage systems, clearly demonstrates the corporate commitment to sustainability.
The supply-side implementation of NZEB principles as demonstrated at the SunCarrier Omega NZEB may be adopted by consumers in various fields. To the growing population of highly eco-concious consumers, this model offers a proven and pragmatic solution to meet their desire to consume only 'green' energy. Another useful application of the above model is for the electrification of those large tracts of inhabited land which either do not have access to the grid, or providing such access and wheeling power in, is prohibitively expensive.
In industries where the availability of power is critical to survival, as in the case of hospitals, the above model provides them energy security, and liberates them from spiralling fuel and utility costs. The Telecommunications industry can power the telecom towers, using this model, and reduce its energy costs in diesel consumption, and significantly reduce the greenhouse gases as a consequence. The manufacturing industry, too, could use this model to provide 'clean' uninterrupted power supply is required to protect the machine tools being used and the jobs being processed, and reduce its dependence on erratic grid power.