Site Power Generation and Utilization: The Four Domains
Mesa Solutions aims to create a more informed customer. This article is directed at giving you a larger more comprehensive grasp on the the four domains of site power generation and utilization. After working in this industry so closely with a team comprised of many with a deep understanding of these products, we are able to disseminate a huge body of knowledge to our customers. The reality is creating electricity, site by site, and utilizing it at an industrial scale involves a lot of carefully thought out technology and, vigorously applied “best practices.” Since the full scope of some packaged technologies may achieve multiple purposes, it may be helpful to divide those purposes up into categories allowing more specific comparisons of options. We define those categories as four “domains.”
The first domain in site power generation is load coordination, this refers to an attempt to reduce site demand by intelligently and logically controlling variable loads. At the level of one big electric motor, this may just involve the soft start technology used to reduce the starting inrush current. For a site with multiple, independent, large motors, a comprehensive control scheme is used to “time” the operation of various loads so, if possible, they are not on at the same, or at least, not creating peak loads at the same time. In either case, the goal is to reduce the site’s natural and overall peak demand.
In demand shaping, we electrically modify the native load shape produced by the equipment at the site. We are creating the load shape. Essentially, we are working to synthesize the average load of the site into as flat a level as possible. Future innovations in this domain may include active devices that pre-store energy and use said energy to fill in peaks and valleys of the native load shape. Currently, there a several devices of a “regenerative” nature that take advantage of physical momentum in certain types of loads to capture energy and return it to the load when needed.
Of course, the big domain is where electricity actually is created. Large, portable generators are available with various types of prime mover engines burning a variety of hydrocarbon based fuels. Further, renewable energy sources such as solar (photovoltaic) are becoming available for certain applications. A big innovation that is forecasted for the not too distant future is Solid Oxide Fuel Cells (SOFC.) SOFCs come bearing the proposition that–at very high temperatures–convert fuels, such as natural gas, directly into electricity with essentially no moving parts. Of course, in real time, planners select and compare available technologies. A good “first pass” filter for evaluating technologies is to look at the unit cost of one kilowatt of capacity, that is, the overall cost of the generating device divided by the electrical output capability of the device. Presently, a good rule of thumb number for generators powered by natural gas reciprocating engines is $1000/kW. As an interesting comparison, photovoltaic panels, in a utility size deployment, approach $2000/kW hour. For the end consumer of these two examples, what matters most is how the providers of these sources structure their investment payback periods.
For providers, the challenge looks the other direction. As an aside, this domain could be defined as the continual search for the lowest cost source of electricity. Providers are constantly looking for innovations in all the domains, seeking to find something that might “add” electrical capacity in an energy saving or energy recycling way, at better economics. Most innovations on today’s technical frontier face challenges in terms of unit cost. For example, some innovations bear the proposition of capturing waste heat and turning it into electricity. The difficulty is, in this example, the innovations have a unit cost of $2500 to $5000 per kW. Meaning, its more economic to use more conventional generation.
Another challenge to alternative innovations is conventional generation keeps improving. Futurists since the 1970’s predicted the costs of solar power would “soon” meet or beat the cost of conventional power generation. Predictably, solar has become more economical over time…but so have conventional sources.
The last important domain in site power generation to consider is applying available sources in the most optimal configuration. Ultimately, site power provisioning may consist of groupings of different types of sources to account for the overall load curve: a base of conventional generation, a bit of renewable, a bit of storage, a fast reacting innovation, etc. And in collections of these groupings, micro-grids, which are loads in a region tied together by a medium voltage backbone circuit, may be the optimal solution.
Site power providers continue to review the opportunities in these domains. There is active research and development in each domain, with potential solutions that merit watching. The fourth domain of optimization constantly challenges providers to try new methods and procedures with existing technology and to develop pricing structures that more closely match end users’ financial preferences. Mesa Solutions sees the value in information consumption from our customers. We are passionate about the subtleties of our industry that can lead to the best service, product, and reliability from which you can benefit.