Fuel cells have been providing energy to the data center industry for over a decade, with many performing far beyond expectations. They were chosen for their reliability with constant loads and efficiency, operating to supplement or replace part of power drawn from the utility. Another touted benefit is their environmental impact, reducing the carbon footprint by displacing those utility loads.
More owners and operators are researching how to incorporate fuel cells as many still consider it a new technology. As people are becoming more aware of what they pay for power as well as being more sensitive about environmental issues, interest in fuel cells increases. With the price of natural gas being stable and dropping in recent years the benefits become even more striking. With the technology being utilized for over four decades, the fear of implementing a new technology is outweighed by the reduction of operating expenses and lower carbon footprint; all of this has increased demand.
Fuel cells have been the power plant in several vehicle types and a lot of prototypes, whether powered natural gas, hydrogen, or other alternate fuels. Because the vehicles need to operate safely with passengers in all sorts of accidental scenarios, fuel cells were vetted by major car manufacturers before introducing them to the wider market. This comfort level with fuel cells being reliable and robust began to convince owners that stationary fuel cells could be scaled to do the same for their data centers.
The sizes of the fuel cells can vary, but a typical individual cell size might be 200 kW with a number of them operating together to provide 1+ MW of power to a block of the data center. And for each hour a MW of power is pulled from the fuel cells the carbon emissions from the site are reduced by up to 20%. In addition, the water savings adds up quickly since the fuel cells do not require water to operate after the initial injection during the start up phase. This is a large savings compared to the utilities which can use over 3 million gallons of water per year when providing a megawatt of power.
The main feature for operators and owners has been the cost savings. The fuel cells, operating at full capacity, have saved 20-25% per year, which was beyond conservative predictions to show an even better return on investment. Most companies and government agencies do not have budgets to experiment with replacing energy sources unless those owners and operators can prove that fuel cells will yield savings.
Computing the costs, savings, and payback from implementing fuel cells can be easily complicated. Often, they are compared to a generator & UPS system setup that is used for continuous power, and the fuel cells typically cost more. The goal is to take a long-term view on the overall ownership and operation of the fuel cells, which will save much more over time. The time frame of that payback is usually what drives owners to move forward with fuel cells or pass; as a simple payback is about seven years, this can be a difficult investment for many entities.
Incentives from the government are an important factor when deriving the payback. Those incentives can be arranged in many complex ways to encourage less green house gas and knowing how much and what the criteria can be changes from state to state and when the installation begins and ends. The power costs vary in the same way, and even the savings can be reduced when a utility discontinues a preferred rate when the power draw is reduced beyond a certain point. Because of this all the details need to be considered in the payback calculations.
When the fuel cells make economic sense then the reliability is considered for study. This factor couples with the aim of many companies that are considering how to move toward a more distributed generator of power that supports more of a microgrid power setup. The long-term trends have been to have power that is more consistent and reliable, whether for a data center, large office building, or campus. With natural gas being a relatively secure energy source, with reliable supply and abundant sources that keep the prices favorably low.
Once in place, dashboards show how much energy each cell is generating and can show comparisons to current utility rates to provide an up-to-date measure of the total savings. This translates to carbon reduction, which can be compared to the number of trees planted or other metrics of offsets that the client would like to see – including how long until the payback is met.