AC vs DC

March 1, 2018

Sponsored by Schneider Electric.

The discussion surrounding AC vs. DC power is not a new one, but the rapid rise in new technology, lead primarily by renewable energy and electronics has brought a new focus to the discussion about AC vs. DC and how it will affect the electrical industry.

We need not return to the debate over power distribution between Thomas Edison and Nikolas Tesla. As we know AC won as the method for power distribution, but that didn’t mean DC went away, rather its use became limited to particular products that required conversion from AC to DC. In this conversion lies one of the greatest issues with AC/DC, namely the loss of power during the conversion process. Each time power is converted there is an average loss of 5% - 20%.[1] And at times multiple conversions are needed before power reaches its end-use. At a time when energy waste is at the forefront of industry conversations power loss is a major issue and driver of potential further adoption of DC and LVDC power use.

Some advocates even feel that with the rising tide of DC powered devices it would be prudent to adopt DC power distribution, although this is not wholly feasible considering our current infrastructure.[2] Rather, we will need to become more efficient in the use of both AC and DC power and attempt to provide the proper power to each item without multiple power conversions.

In every home there are items that use AC and DC power, however, items requiring DC are on the rise (televisions, computer equipment, LED lighting, solar cells). Because of this there are a number of pilot programs that have focused on developing residential homes with wiring and outlets that are both AC and DC capable, essentially testing the residential market for the rising trend in net-zero and smart-homes.[3] Internationally Japan and Korea have lead the push for DC power within the home, Korea has even completed a residential DC power demonstration project with DC distribution and appliances that claims to have shown a modest increase in efficiency gain.[4]

In Canada there is a drive for increased use of renewable energy and energy efficiency within the home. The adoption of solar power is one of the most prominent methods and has seen substantial advances in recent years, particularly in Ontario. This push is being driven by numerous incentive programs that are making renewable energy sources available to consumers.  Other provinces are now following suit with comparable incentive programs. See Solar Capacityyour provinces incentive programs here. Canada is also a leading proponent of the Paris Climate Agreement, and to meet those ambitious but necessary goals we will need further adoption of renewable energy in all electrical sectors, especially the residential.

As we strive to meet these goals there will be a substantial increase in personal investment in renewable energy, and in particular solar energy. The Canadian Solar Industries Association’s (CanSIA) Report Roadmap to 2020 notes that “about half of Canada’s residential electricity requirements could be met by installing solar panels on the roofs of residential buildings.”[5] The rise of net zero homes is working to go beyond this and create fully self-sustaining homes utilizing renewable energy and home energy storage.

There is no question that the positive attitude toward renewable energy will “Create a population of Canadians that want to be “prosumers” – Canadians who both produce and consume electricity and feel motivated to manage their own electricity future efficiently. This will drive demand for residential solar electricity systems.”[6]

Solar AlbertaAs the residential solar market increases a growing number of homes will be developing and storing DC power. Even those locations that sell excess power to energy providers are losing power as it must first be converted to AC to be transferred through existing distribution lines. Thus, home energy storage is on the rise.

The increase in residential use and storage of DC power from renewable energy will continue to permeate into the existing electrical market, with a large impact likely focused on the residential electrical contractor. In Canada, 57% of electrical contractors have 4 or less employees, and control a substantial portion of the residential sector.[7] As this sector moves toward more renewable energy, and in particular net zero homes, small electrical contractors are ideally positioned to continue their expansion into the renewable energy sector.[8]

There has been the concern that with new technology and trends, in particular DC and LVDC, some of the work done by traditional electrical contractors will be absorbed by niche or specialized companies. With this rising trend the ECAO has noted in Power Shifts, The impact of low-voltage DC power developments on the Canadian electrical market that “as an industry we must gain a better understanding of the outside forces that are moving into the inner folds of our channel. Consideration must be given to whether we form relationships with the new emerging players – or do we allow them to become competitors working in isolation from our channel.”[9] Collaboration will positively serve the industry, but electrical contractors will also need to ensure they remain aware of market trends and demand from the growing residential renewable energy market and smart home adoption and envelope this demand within their service abilities.

Electrical Contractors such as Garraway Electrical, an electrical contractor in Ontario, has adopted this initiative. Garraway’s has taken the step to become an “experienced installer of solar power, whether it be an off grid, stand alone system, or a grid tie.”[10]

Similar examples can be seen in Electro-Federation Canada’s 2016 Contractor Research Report. The report includes an interesting point made by one of its focus group members who noted that “Three-quarters of our business rightSchneider Electric now is based on new technology, so this has a big impact on my business. We primarily do energy-saving projects…and have the need to design and build energy-saving projects, so we use all the kinds of new technology, mechanical and electrical equipment. Just five years ago, it was the contrary; new technology made up 25% of our business and 75% were regular electrical jobs.”[11]

As it stands it is either a direct solar installer or an electrical contractor that is called upon to educate individuals on renewable energy and implement such systems. If we consider incentive programs from across Canada provincial programs recognize the need for residential electrical contractors to engage with solar installations. Manitoba’s Solar Energy Program identifies that “a solar installer or electrical contractor can help you with sizing the solar PV system to suit your budget and space requirements, including the ideal orientation of the system. They can discuss options for different levels of solar panel efficiency and give quotes and expected payback periods.”[12] Further to this, if we consider Canadian directories of solar installers, such as the Alberta Solar Providers Directory we can see that electrical contractors are increasing their presence in the market alongside niche specific energy companies. Electrical contractors have the unique ability to provide complete system installation, including any necessary changes to your homes wiring or current capacity. Yet another reason why electrical contractors are an optimal choice for residential renewable energy installation and maintenance.

Angel Pedrosa, Retail Marketing Director at Schneider Electric notes that “as the trend toward further renewable resources expands electrical contractors will be presented with further avenues of opportunity within this growing sector, and with it the need to work with both AC and DC power and their various applications.”

EV SalesAlso, part of the “Go Green” initiatives in Canada is the push for Electric Vehicles (EV) which store DC power. Canada saw an increase of EV sales by 56% in 2017 over 2016, driven primarily by Ontario where sales in 2017 were 96% higher than in 2016.[13]

Most EV’s have the option to charge from AC or DC charging units, but the conversion of AC to DC power, which happens in an internal charger within the EV is slow and again inefficient due to power lose. Direct DC charging is much faster and more efficient and as more homes are adopting renewable energy the best option would be to directly charge an EV using the DC power that the home has produced. However, with many EV chargers operating in both AC and DC, and the fact that not all residential homes requiring EV charging yet operate on renewable energy, it is the small electrical contractor that will often be called upon to implement required systems or provide the necessary converters depending on the home’s need. If you go to Tesla’s support page they have a ‘Find an Electrician’ link that will direct you to electrical contractors in your local area capable of installing EV chargers.

We have focused here on the rise of renewable energy as it has far reaching implications for the use of DC power, particularly in the residential sector. As the useEV Charging of such technology continues to trickle down and be adopted directly by consumers there will be a rise in the need for electrical contractors to provide services in both AC and DC.

We also cannot overlook systems that have in some instances been in place for years but have been outside the realm of the electrical contractor. However, as these systems advance it is the electrical industry that will need to adapt. ESA’s John Calabrese noted, when discussing PoE, that “the biggest thing is just recognizing that yes; this is an electrical installation even though it looks like a data system—maybe we shouldn’t have been ignoring this all these years . . . the desktop phone has been PoE for quite a long time but nobody realized it. You just think of it as a communications device, but it’s powered. Security cameras are also powered and have data over the same cable. We have long thought of these examples as data systems so they were exempt from the Code. We need to shift our minds to recognize they are actually an electrical installation; it’s a change of paradigm.”[14]

The recently released 2018 Canadian Electrical Code now has a section devoted to PoE (CEC Part 1 Subsection 16-300) and its installation. In this instance electrical contractors now have a guideline to work from, a trend that is likely to continue as electricians delve into the expanding realm of new technology trends and the acceleration of DC and LVDC power.

We have identified and considered some of the rising trends that are bringing new awareness and consideration to the DC/AC power conversation, and the discussion has just begun. The rapid adoption of new technology and renewable energy and their DC power use will continue to push the topic to the forefront of conversation and will drive new industry directions and opportunities. Identifying these trends and opportunities will be advantageous for electrical contractors as it presents a new and widening service avenue, and for those that embrace it the ability to meet the changing demands of energy consumers.

Sources:

Images:

1) https://www.neb-one.gc.ca/nrg/sttstc/lctrct/rprt/2017cnddptnrnwblpwr/slr-eng.html?=undefined&wbdisable=true

2) https://solaralberta.ca/faqs

3) Schneider Electric DC Power System

4) https://www.fleetcarma.com/electric-vehicle-sales-in-canada-q3-2017/

5) https://procarreviews.com/best-ev-charger/

 

[1] Gregory Reed, 9 Reasons Why DC May Replace AC, http://www.electricalindustry.ca/latest-news/1018-9-reasons-why-dc-may-replace-ac

[2] Peter Fairley, MIT Technology Review, https://www.technologyreview.com/s/427504/edisons-revenge-the-rise-of-dc-power/

[3] https://www.digitaltrends.com/cool-tech/nexthome-dc-powered-home/

[4] Karina Garbesi, Vagelis Vossos and Hongxia Shen. “Catalogue of DC Appliances and Power Systems,” Energy Analysis Department, Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory. http://efficiency.lbl.gov/sites/all/files/catalog_of_dc_appliances_and_power_systems_lbnl-5364e.pdf

[5] CanSIA, Roadmap to 2020, http://www.cansia.ca/uploads/7/2/5/1/72513707/cansia_roadmap_2020_final.pdf

[6] CanSIA, Roadmap to 2020, http://www.cansia.ca/uploads/7/2/5/1/72513707/cansia_roadmap_2020_final.pdf

[7] Pathfinder p. 49

[8] Searches of local electrical contractors across Canada reveal that many contractors have recognized the increasing demand of the renewable energy market and are already expanding their capabilities to address this demand.

[9] ECAO Power Shifts, The impact of low-voltage DC power developments on the Canadian electrical market. The Ontario Electrical Contractor 55 (4) (2017) p. 24

[10] http://www.garraways.ca/residential.php

[11] Electro Federation Canada 2016 Contractor Research Report, p. 10

[12] https://www.hydro.mb.ca/environment/solar.shtml

[13] https://www.fleetcarma.com/electric-vehicle-sales-in-canada-q3-2017/

 

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