Wind power or wind energy is the use of wind to provide the mechanical power through wind turbines to turn electric generators and traditionally to do other work, like milling or pumping. (Contributed)

Dyer: Balancing variable solar and wind energy

Kristy Dyer has a background in art and physics and consulted for Silicon Valley

Wind and solar energy have hit a critical new milestone: it’s now cheaper to build a wind or solar farm than it is to build a new natural gas plant. There is no “renewable penalty” for electricity now and responsible utilities need to start planning for a much larger share of solar and wind energy.

READ MORE: Revelstoke Dam expansion environmental review completed and waiting for ministry approval

That doesn’t mean that it is easy to build an energy portfolio heavy on renewables. Wind and solar are intermittent sources of energy: they produce electricity only as long as the sun shines and only as long as the wind blows.

READ MORE: Summerland approves solar project

It is possible to “load balance” wind and solar in the energy portfolio the same way we handle any sudden high electricity demand: using natural gas peaker plants as a backup source. These peaker plants are designed to come on during times when extra electricity is needed and then shut down quickly when the load returns to normal. Peaker plants could be run when wind energy drops or to cover for solar after the sun has gone down.

READ MORE: B.C. examines new directions for renewable electricity projects

It is also possible to improve the match between solar energy and electricity demand by merely adjusting the orientation of a solar array. Solar energy is available during the day. People use most of their power during daylight hours. This isn’t a bad match — except at six PM when everyone gets home from work. At that time the sun is low on the horizon and people are coming home and turning on appliances. This is the “duck curve” problem California faces.

Some California utility customers are on a “time of use” plan. Rather than a flat rate, they pay more for electricity at peak times and less for off-peak electricity. In these regions some contractors are increasing the size of solar arrays by 10 percent and orienting the array slightly to the west, to better match the “home from work” peak.

Wind energy benefits from “geographical diversity”

Wind energy benefits from “geographical diversity”. If you build wind farms that are separated by large distances, there is a good chance that the wind will always be blowing at some of your sites. Since wind energy comes from regions that are often far from big cities, this means you have to have large capacity transmission lines. These lines bring electricity from remote areas to the cities and allow you to take advantage of different weather at the different sites.

It would be better if you could just store the energy when you have it and then withdraw it when you need it. Battery storage has improved greatly and it has become more common to see solar and batteries packaged as “solar+storage”. The solar array to be built in Summerland is solar+storage and Summerland expects to use it to reduce peak electricity costs as well as providing power once the sun goes down.

The solar array to be built in Summerland is solar+storage

A special kind of hydro has been used since 1908 as energy storage. This “pumped hydroelectric energy storage” can be used to save money during peak periods or used to even out renewable energy. For energy savings, water is released from a high reservoir to a low reservoir during peak periods, when electricity is expensive. Then during off-peak hours it uses electricity to pump water back up to a high reservoir. Even when a hydroelectric storage plant doesn’t make money off the exchange, it is providing an essential function balancing the electric load. In combination with solar or wind, hydroelectric storage can even out the intermittent energy output of these renewables. Canada has a single hydroelectric storage site: the Sir Adam Beck Pump Generating Station in Ontario. The US has 30 sites, with a capacity of 22 GW. This type of storage only works where there are hills or mountains, providing a high and low reservoir.

Hydro power is an excellent match for intermittent renewables such as solar and wind

Hydro power in general, either hydroelectric dams or pumped storage, is an excellent match for intermittent renewables such as solar and wind. When the wind blows and the sun shines, electricity can be used from solar and wind. At night and during lulls in wind, hydro can provide load balancing and reliable backup.

Missed last week’s column?

Dyer: Financing energy efficiency

Kristy Dyer has a background in art and physics and consulted for Silicon Valley clean energy firms before moving (happily!) to sunny Penticton. Comments to Kristy.Dyer+BP@gmail.com

Kristy’s articles are archived at teaspoonenergy.blogspot.com

Like us on Facebook and follow us on Twitter.

Environment

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

A pair of Okanagan Regional Library reference librarians have created a podcast called Hard Cover that takes a zany but informative look at books, libraries and librarians. (File photo)
Okanagan reference librarians produce quirky podcast

Davin Helkenberg and Peter Critchley are behind Hard Cover

Shuswap Ringette U16 team athletes: Brianna Congdon, Mackenzie Packer, Brooklyn Wright, Sequoia Robinson, Camryn Petty, Alecia Hughes, Kaelah Riley and Kellan Mooney. The team photo was photoshopped together by the team manager in order to maintain physical distancing due to COVID-19 restrictions. (Contributed)
Shuswap Ringette players shine in skills competition

Shuswap Ringette’s U16 squad earns highest scoring team in the province

In this Dec. 18, 2020 photo, pipes to be used for the Keystone XL pipeline are stored in a field near Dorchester, Neb.  THE CANADIAN PRESS/AP-Chris Machian /Omaha World-Herald via AP
Letter: In light of Keystone decision, Trudeau, Kenney fail to deliver real support for workers

Writer says Biden’s cancellation of pipeline more than just a political gesture

Eagle River Secondary Grade 9 student Cody Hutchinson spearheaded the Digital Detox Challenge in which participants will give up their cell phones during school days for two weeks straight. (Contributed)
Sicamous student challenges himself, peers to go nine school days cell phone free

Cody Hutchinson hopes Digital Detox Challenge will give students opportunity to reconnect

A sign indicating a COVID-19 testing site is displayed inside a parking garage in West Nyack, N.Y., Monday, Nov. 30, 2020. The site was only open to students and staff of Rockland County schools in an effort to test enough people to keep the schools open for in-person learning. (AP Photo/Seth Wenig)
4 more deaths, 54 new cases of COVID-19 in Interior Health

This brings the total to 66 deaths in the region

Dr. Penny Ballem, a former deputy health minister, discusses her role in leading B.C.’s COVID-19 vaccination program, at the B.C. legislature, Jan. 22, 2021. (B.C. government)
B.C. holds steady with 407 new COVID-19 cases Tuesday

14 deaths, no new outbreaks in the health care system

Lesley Lutes, UBCO professor of psychology and director of the Centre for Obesity and Well-being Research Excellence. (Submitted)
UBCO psychologist part of Bell Let’s Talk virtual panel tonight at 6 p.m.

Panel will talk about coping under the stress of this pandemic

Vaseux Lake in winter. (Facebook)
Dogs rescued after falling through ice on Vaseux Lake

Good Samaritans saved the trapped dogs

Superstore
Three employees test positive for COVID-19 at Okanagan Superstore

Penticton 7 Eleven has reopened after closing for a week for COVID

B.C. Premier John Horgan speaks at B.C. legislature on the province’s mass vaccination plan for COVID-19, Jan. 22, 2021. (B.C. government)
COVID-19 quarantine not an option for B.C., John Horgan says

Apres-ski parties increase risk, not interprovincial travel

A rendering of the proposed “Aqua” resort in Kelowna’s Lower Mission area. (Contributed)
Towering waterfront resort planned in Kelowna

Mission Group’s ‘Aqua’ resort has been in the works for more than a decade

“My grandma always just said…making people smile is the most important thing,” says Nicholas Kruger. (Chehala Leonard, Local Journalism Initiative Reporter)
Entrepreneur Nicholas Kruger nominated as Okanagan community changemaker

With humour and knowledge, Nicholas Kruger says it’s important to give back

Okanagan Symphony Orchestra music director Rosemary Thomson in action at the podium. Photo by Lynda Miller.
Kelowna filmmaker gets funding to create new ‘Local Heroes’ documentary

The documentary will be focused on the director of the Okanagan Symphony Orchestra and Opera

Worker at Swartz Bay terminal on Monday, January 20, 2020. (THE CANADIAN PRESS/Chad Hipolito)
Former BC Ferries employee alleges he was fired because of his race

Imraan Goondiwala has been granted a BC Human Rights Tribunal hearing

Most Read