Alternative and Renewable Energy

Solar, Wind, Hydro, Fuel Cells, Bio-Gas / Micro-turbines, and other energy sources are of great interest to data center operators due to uncertainty in raw energy costs, continuity of supply, source CO2 emissions, as well as general environmental best practices and community involvement. Depending upon the location of the data center one or more of these technologies may be available at least on a partial basis. We aim to cover them from a data center perspective with information, resources, and examples of technologies that are viable for high-density power use required for data center operations. We will also explore some of the issues involved with deploying these technologies such as reliability, interconnection, and typical cost/incentives.

One overarching consideration with Alternative / Renewable Energy one should keep in mind is that most of these technologies are difficult to scale to a large data center. Hence the USGBC (United States Green Building Council) in their LEED (Leadership in Energy and Environmental Design) rating system assign the maximum points to a 20% of total site power production level. This may change with time as more data centers embrace on-site renewable energy production and demonstrate a willingness to achieve higher levels of performance.

Solar:

Photo Voltaic (PV) is the generally preferred form of solar power for data centers and is often the first technology that comes to mind when considering renewable energy systems. Numerous regional tax credits, incentives, rebates, etc. are available around the globe to encourage the adoption of solar PV. However Solar Thermal is beginning to gain broader market acceptance, is capable of equaling the costs of “peak” power plants, and is of a scale suitable for mega data centers or closely-coupled large data centers. We provide information, examples, and resources for both of these technologies.

The number of data centers deploying solar power is growing rapidly. Please contact us if you would like to list your site and provide details and/or a case study on the project.

Wind:

Often sited as the best-cost technology for renewable energy production, large-scale wind (large turbines in the MW class) when sited with favorable wind are capable of equaling typical low-cost coal power sources. Large-scale wind power is often limited to those power developers / investors willing and able to develop fifty mega-watts or more of power at one time. Data center operators may want to team with such firms via power purchase agreements (PPAs – also available in solar power applications) to lock in favorable electricity rates, CO2 free power, along with guaranteed access as part of a site development incentive thereby enabling regional incentives for the wind developer and favorable power for the data center.

Mega data centers or sites where multiple large/mega data centers will be in close proximity should consider forming a joint venture with appropriate energy professionals to develop their own wind power facilities.

Many utilities, SCE and PG&E as examples, already produce a significant portion of their power from wind. Data centers in those power grids may already be receiving 30% or more of their power from wind and/or a combination of alternative / renewable energy sources.

Low-power and architecturally integrated (AI) wind are a recent newcomer to the data center space. Depending upon the power requirements of the data center these wind systems may be able to provide anywhere from a token amount of total power to 100% of the site’s IT load requirements. Low-power and AI systems benefit from easy permitting, minimal site impact, improved aesthetics, and minimal community impact. These renewable energy systems can often be retro-fitted to existing commercial buildings with little to no impact to daily operations.

Hydro:

Rapidly becoming the renewable energy power source of choice for mega data centers in large part due to the very low cost of power. Hydro power is not often a viable solution for those who want to develop their own power source. The permitting process to develop a new hydro source is beyond the scope of all but the largest government owned data centers. Like wind there are small-scale hydro solutions on the market however the overall site research, preparation, and permitting process still leaves this more in the realm of utility companies who are best equipped to manage the entire process.

Fuel Cells:

This alternative energy source is beginning to find acceptance within data centers especially when one can take advantage of the entire power cycle of fuel cells including the waste heat portion as a source for absorption chillers. These medium-sized fuel cell power plants, typically in the 200 to 500kW class, when matched to an equal data center IT load and backed with proper incentives can achieve favorable rates of return.

In smaller-scale applications fuel cells are beginning to replace the traditional battery plant for long run-time applications. Here the power density of fuel cell stacks and near maintenance free operation along with the near zero harmful emissions characteristics along with tax incentives make fuel cells worthy of consideration.

Bio Gas / Micro-turbines:

Often viewed as a co-generation source micro-turbines when combined with on-site available bio-gas or natural gas may be a viable alternative energy source. Though not CO2 emission free these systems may be included as part of a site redevelopment effort as they assist the developer in mitigating known hazardous gas issues on the site while simultaneously providing a “green” power source. As with all such power systems one needs to verify any potential tax or regional incentives / rebates early in the decision process as well as to investigate any sustainable site credits from USGBC. Regional permitting issues may come in to play necessitating a joint partnership with either a municipality or utility to move the development forward.

Other:

Though technically neither a renewable or alternative energy source flywheels represent an interesting and energy efficient replacement for traditional lead-acid battery plants. We have included relevant information on high-speed small foot-print flywheels that are currently being used in numerous data centers.

Geo-thermal is yet another alternative energy source however though gaining in market acceptance is extremely limited by geography in availability and the costs for development require utility scale operations in order to achieve reasonable production prices.

Tide and wave power are enjoying increased research within the academic community. Currently like geo-thermal the costs associated with these renewable energy sources leave them in the realm of major utilities.