Most solar energy comes from single-sided panels laid flat or at an angle on a roof or in a field. However, vertical bifacial solar panels are starting to make their way onto farms and other places. These new panels use less space and can generate more energy, making them attractive.

A vertical bifacial solar panel is, simply, a panel with photovoltaic (PV) cells on both sides that is installed upright rather than horizontally to face east and west, so they generate electricity with sunlight that reaches one side in the morning and the other in the afternoon.

Research Shows Higher Output

Producing energy on both sides appears to lead to higher output. A 2018 study by LONGi, for instance, showed that vertical bifacial solar modules can increase energy yield by 5-30 percent, depending on factors such as the region, ground surface reflectivity, installation height, mounting, and inverter choices. Vertical bifacial solar panels have two energy peaks, one in the morning and one in the afternoon. Because they do not face south, bifacial PVs mounted vertically tend to stay cooler and that also adds to their productivity.

In addition, bifacial panels can benefit from the albedo effect when sunlight hitting the ground on a light surface is reflected back toward the panels, contributing to the energy generation, so they also perform best on ground surface with high reflectivity (high albedo), such as flat white roofs or sand.
Vertical panels also are less likely to be affected by snowstorms and hail.

While inverters clearly do not get the attention solar panels do, and they’re often almost unknown to solar energy users, they are critical to system performance and even grid reliability. New technologies are enabling far better performance.

How Inverters Work

At a fundamental level, inverters convert direct current (DC) electricity generated by solar panels or other renewable energy sources into the alternating current (AC) electricity that homes and businesses use. AC and DC are two types of electric current that differ in the direction of the flow of electrons. AC alternates its direction periodically, while DC flows in one direction only. AC is more efficient for transmitting power over long distances, while DC is more stable. Historically, electrical power has been predominantly generated by burning fuel and creating steam, which spins a turbine generator to creates AC power. Home appliances were designed to use AC voltage from the local grid and cannot run on the DC provided by solar panels.

Solar inverters are DC-to-AC power conversion devices, so they can solve this problem. Inverters are thus one of the most important pieces of equipment in a solar energy system.

A key reason why buildings are so important for decarbonization is that, according to the Washington Department of Commerce, “buildings represent approximately one-fifth of Washington’s greenhouse gas emissions. This includes emissions related to electric generation. The greatest portion of the sector’s emissions come from the direct combustion of natural gas and other fossil fuels in buildings for space heating, water heating and cooking.” Moreover, the World Economic Forum (WEF) wrote, buildings offer more energy-saving potential than industry or transport.

Energy-efficient buildings create comfortable living conditions with the least possible amount of energy consumption, researchers Janamejay Gupta and Manjari Chakraborty explained. 

The growing impacts of climate change have also made the decarbonization of buildings essential. Making buildings “net zero”, whereby greenhouse gases (GHG) emissions are reduced as close to zero as possible and any remaining emissions are offset, is a key strategy. For houses, Efficiency Vermont said, net zero is the balance between the power a home needs and the renewable energy homeowners can generate to match the need. “With new heating technology and lower-cost renewable energy systems, any home can get to net zero”. Solar is currently the most affordable way to generate energy, while air sealing yields the greatest energy savings and weatherization as well as usage of smart devices establish also reduce energy waste.

Rising demand for electricity due to EVs as well as other devices and shortages of additional capacity threaten electricity reliability across the United Stages. Utilities in Washington State and across the nation are developing and enabling Distributed Energy Resources (DER) to solve the issues. 

DER are electric generation units or other energy services that are located close to where electricity is used, such as homes or businesses. DER can include renewable energy sources like rooftop solar, as well as energy storage devices like batteries, and smart appliances that can interact with the grid to reduce or time energy consumption. 

At the 2023 Solar Summit, held October 20, 2023, at South Seattle College, Nora Hawkins, Senior Energy Policy Specialist Washington State Department of Commerce, and a Solar Washington Board Member, invited and moderated a panel on Strategies for Clean Energy Storage. The panel generated a lot of interest and many questions, so we decided to provide a summary of it, based on the transcript of the presentations.

Development of solar power in Washington state continues to grow, bolstered by 2019 Clean Energy Transformation Act (CETA) that commits Washington to have electricity free of greenhouse gas emissions by 2045. While the biggest need for electricity is in the more populous western half of the state, much of the development is on large solar farms in the sunnier eastern half. In February 2023, for example, AVANGRID announced that it had started operating its 150-Megawatt (MW) Lund Hill solar farm in Klickitat County, the state’s largest photovoltaic plant. The Washington state Department of Fish and Wildlife (WDFW) told the Seattle Times that more than 40 proposed solar projects would collectively lease more than 80,000 acres.

Solar farms are becoming increasingly difficult to site. Highly attractive locations can be home to endangered species and critical habitat, or they can be very attractive for farming, residential development or recreation. Directed by a budget proviso passed by the Washington State Legislature, the Washington State University (WSU) Energy Program carried out a Least-Conflict Solar Siting study on the Columbia Plateau as a pilot project. The Columbia Plateau region is about 14,242,020 acres, not including Tribal reservations. While over 6,777,000 acres could be considered highly suitable for solar development, just under 212,000 acres were deemed low conflict for environmental conservation, farmland, and ranchland, and ranked “very high,” “high” or “moderately high” for solar development suitability after maps were reviewed by stakeholders, including ranchers, farmers and environmentalists.

The good news for anyone who wants to work in the solar energy industry is that workers are in demand. It’s a different story for employers who need staff, though, as many face a shortage. Creativity will be needed to find enough people to support growth within the industry.

The Solar Industry needs More Installers - and Electricians

U.S. solar energy installations soared 47 percent in the first quarter of 2023, according to research by Wood Mackenzie, as easing panel supplies alleviated industry gridlock and allowed stalled projects to be completed. Wood Mackenzie expects the solar market to triple to 378 GW by 2028.

That growth as well as the Inflation Reduction Action (IRA) will help create hundreds of thousands more jobs, according to the National Solar Jobs Census, with solar employment nationwide forecast to rise from 255,037 in 2021 to 538,000 by 2032.

Many of those jobs are going unfilled, however, with recent data showing growth in demand for green skills that exceeds supply. Washington State Governor Inslee told Politico that “having the technicians and the engineers and skilled mechanics, that is going to be a challenge in the United States.” That shortage exists even though the IRA includes strong incentives for employers to pay good wages and benefits, with tax credits for renewable energy and energy efficiency projects up to five times higher if contractors and subcontractors use registered apprentices and journeymen workers and pay prevailing wage rates.

While Washington State has some of the most aggressive climate goals in the United States, the inadequacy of the current electricity transmission infrastructure and slow permitting processes threaten the state’s ability to achieve its objectives.

Electricity Transmission Bottlenecks Threaten Climate and Resiliency Goals

Requirements for electric utilities to shift to solar and wind for their power generation are key parts of what gives Oregon and Washington some of the best climate plans in the country, Sightline Institute observed (Northwest States Need to Build New Power Lines, Fast - Sightline Institute). Indeed, the goal for the state of Washington is to use only clean energy by 2045. Northwest Power and Conservation Council (NPCC) concurred (Transmission | Northwest Power and Conservation Council (nwcouncil.org), saying the Northwest is blessed with such abundant and inexpensive hydropower, solar and wind power that they are beating the price of practically every other type of power.

Net energy metering (NEM) is largely being used in Washington for behind the meter or customer-sited solar energy generation, but it can compensate various types of distributed, energy generation. According to the National Renewable Energy Laboratory (NREL), net energy metering can be defined as “a metering and billing arrangement designed to compensate distributed energy generation system owners for any generation that's exported to the grid.”

When solar energy is produced by solar panels, some or all of it is consumed on site. Unless the solar project is quite small compared to the amount of electricity consumed on site, some power will be exported to the grid and other customers, and the solar-equipped customer gets credit for the excess production. On a cloudy, rainy day, when panels aren't producing enough energy, the utility grid will feed your home energy and count that energy against the credits you've banked overtime.

This article summarizes the presentations made by Washington Department of Commerce's Nora Hawkins, and Shane Frye, with SnoPUD, both Solar Washington Board Members, at a May 10 Solar Washington Webinar. The full webinar, titled Net Energy Metering in Washington, is available online.

When we look at who supplies our electricity, we think of local utilities. Puget Sound Energy, Avista, Pacific Power and a host of other companies and PUDs supply power to consumers and companies around Washington state.

However, factors such as more frequent power outages and a desire for energy independence and community resilience are causing a desire for more reliability. The US Department of Energy (DoE) said natural disasters and physical or cyber-attacks threaten the grid’s ability to provide power, which inconveniences customers in some cases and can cut people off from critical services. For example, attention-grabbing headlines in several newspapers last week (e.g., NY Times) warned that, according to a recent study, 800,000 Phoenix residents could require emergency care and 12,000 could die in the event that an extended power failure happened during a heat wave. Throughout the country, the grid is being challenged by ever rising energy consumption and ageing infrastructure. Moreover, some remote rural communities do not have ready access to electricity from utilities or want an alternative.

Communities, companies and government agencies are increasingly looking at installing microgrids to achieve their goals.