By Scott Kriner, Green Metal Consulting
Just about everyone has seen the bulky inverter units on their cords used to charge laptop computers, smart phones, i-pads and numerous other small electronic devices. Even rooftop photovoltaic panels require inverters to change the DC power generated by the modules to AC for use inside the building. As the building construction industry moves closer to net zero energy designs, there is a growing need for buildings to generate their own electricity and to rely less on the traditional large utility grid. Small micro grids on a building or in a neighborhood are being used more and more. In many cases some electricity is used by the buildings on the micro grid with the excess energy that is generated by PV or other renewable sources being pushed back to the grid. But according to EMerge Alliance, the utility grid can only accept 15% of its power from distributed sources, such as rooftop PV, wind or micro grids.
USGBC and the EPA tell us that buildings consume more than 65% of our nation’s electricity. And the consumption of electricity continues to grow in the US and worldwide. The demand for electricity has doubled from 1990-2011 and it is projected to grow 81% from 2011 to 2035. (EMerge Alliance) The explosion of affordable small electronic devices in homes and buildings is partly responsible for the growth. Aside from personal devices and gadgets, there are dimmers, occupancy sensors, speed controls, smoke detectors, motion detectors, and others that are on continuously. In an article from Building Operating Management, EMergeAlliance President Brian Patterson states that “combined information and computer technology devices will nearly equal the total load of lighting homes and businesses in terms of raw power consumption by the end of this decade.” Almost every device today runs on DC power meaning that the AC power from the utility grid needs to be converted. And whenever AC is converted to DC there is an energy loss. That works against the net zero energy concept.
And to make matters worse, the reliability of our existing grid has come into question. Electric power outages have significantly increased over the past two decades.
Houston, we have a problem!
In today’s society, whenever we are looking for answers we turn to the internet for help. And in this situation where improvements in the grid have lagged behind other innovations, we can turn to the internet again. But not simply to Google “HELP!”, but to look at the internet itself. In just 40 years, the internet went from being completely tied in to central data production using large mainframes to today where the majority of data production takes place on small personal electronic devices. Part of that growth was due to the federal government supporting the Advanced Research Projects Agency Network and the US Congress (with a little help from Al Gore) to deregulate the internet in order to allow the privatization of the network. During that same 40 year period in which the internet became a part of everyone’s life, the electric power infrastructure didn’t change much. We are still relying on electricity being generated at large power plants and then being distributed to buildings.
Is there hope? What is the Next Big Thing? It is called the Enernet. This term is defined by EMerge Alliance as “an electrical network infrastructure that connects electricity generation, storage, and device loads between and within buildings and other facilities around the world. The real question is whether we can evolve an internet of electricity – the Enernet – and do for power what the internet did for data? Many say that this is within reach because we can use the internet to accelerate the development of an Enernet.
In simple terms, the Enernet would be able to provide buildings with DC power without having to convert AC to DC. It is composed of two elements : hardware (devices and connective infrastructure) and software (protocols and standards). The hardware would take the form of a microgrid. Each microgrid must be designed with the ability to be autonomous at times, like how a laptop can continue to function when it is unplugged.
This transformation will not be easy, but the potential benefit is staggering. There are some principles that are guiding the effort to create the Enernet such as:
- It must be easy to connect and collect site based clean energy while providing access to the utility grid
- It must be able to store power for use when production is not taking place
- It must provide power for a range of small devices up to large appliances or building mechanical equipment
- It should use a form of DC power whenever possible
- It must be simple, reliable, resilient and efficient, convenient and safe.
Emerge Alliance suggests that “the increasing amount of native DC power generated from renewable energy sources like solar or wind must also be converted to AC electricity to be compatible with existing AC distribution methods. These conversions, in both directions, result in significant losses of electricity and associated wasted energy. They also add to the complexity and reduced reliability of the overall electrical system. Efforts to create a Smart Grid need ‘smarter buildings’ that can minimize these conversion losses, improve a product's reliability, and reduce the overall load on our world's energy resources.”
According to EMerge Alliance, some microgrid concepts are already being evaluated by private users industry, government and academia. Standards are being developed through an open consensus process. A consortium of companies, private and public organizations has been assembled to work on the hardware and software for the new networks.
The Enernet is to power as the Internet is to data. This topic was discussed at the recent Greenbuild conference in New Orleans, and the subject served as a white paper for one of the show floor education credits. The subject has also been reported in trade publications, most recently in Building Operating Management. The clear driving force to-date has been EMerge Alliance (www.emergalliance.org). We may end up telling our grandchildren about how our generation was so inefficient in the way we used to generate and distribute electricity. This could actually be the “Next Big Thing” !