US lab reveals top findings for hybrid solar, storage plants

Image: Sharp

US government researchers have collected 10 observations from recent research papers that look at solar- or wind-plus-storage power plants in the United States.

From pv magazine USA

The US Department of Energy’s Lawrence Berkeley National Laboratory (LBNL) has released a top 10 list of observations on co-located wind or solar-plus-storage (hybrid) projects.

LBNL is covering the topic due to rising deployment and interest in such hybrid facilities. Assuming that future project queues can be used to predict the number of actual hybrid power projects that will get built, hybrid systems already make up 42% of the future US potential for 675 GW of solar generation capacity. California’s solar queue, for all intents and purposes, is a solar-plus-storage queue, with its 95% coupling rate.

As of the end of 2021, 5.9 GW of solar was coupled with energy storage, along with 750 MW of wind-plus-solar-plus-storage. LBNL noted the exponential growth of this type of capacity, which is up 133% since the end of 2020.

The fundamental reason that solar-plus-storage works is that the price of batteries has come down to a point where it now makes financial sense. Battery pricing has declined by roughly 25%, from $40/MWh to $95/MWh of PV in 2017, to $30/MWh to $75/MWh of PV in 2021.

Second, and more importantly, LBNL modeled the revenues versus the costs of adding batteries to solar. They found that the value gained by adding energy storage to solar and wind exceeds the costs.

Taking into account the battery inverter versus solar plant inverter size, LBNL found that adding four hours of energy storage to a power purchase agreement (PPA) increased the price of that agreement pretty linearly. Considering the most popular ratio of solar vs. battery inverter capacities – 1 MW solar to 0.5 MW batteries providing four hours of storage – the addition of energy storage increases PPAs by $0.01/kWh.

LBNL also sees that there are financial penalties associated with the current techniques of coupling solar with energy storage. For instance, if the solar power is fully using the site’s interconnection at any point, the batteries cannot. Also, if the batteries must fully charge from the onsite solar to meet incentive requirements, that can be a penalty for hybrid systems, resulting in a slightly less financially efficient system.

In terms of financial incentives, the Federal Investment Tax Credit seems to be motivating hybridization. Without this incentive, it is believed that there would be more standalone energy storage.

Since California dominates the volumes of hybrid solar plants in the queues, it also heavily influences the averages. Leaving California’s four-hour heavy market (which is at least partially driven by an evening peak period that lasts four to five hours), the researchers found that California’s batteries tend to have shorter durations in most other markets.

The chart above models the value of energy being delivered by hybrid systems as more battery duration – from two to eight hours – is added to a facility in various power grid regions around the nation.

There is still a lot of learning going on with these technologies. For instance, a 100 MW solar farm plus a 50 MW battery does not equal a 150 MW power plant in terms of capability. Having an intermittent, highly predictable solar generation resource, coupled with an instantly dispatchable multi-talented re-generation battery resource means that sometimes interconnection must be shared – and it’s usually the battery that takes a backseat to the solar facility during generation periods.

This is the hybrid penalization referenced earlier. Asset owners and markets are still learning how to maximize the utilization of these resources.

The document notes that the ancillary service markets provide valuable revenue streams to this young battery market, but that this service market quickly sells out. These large scale markets of independent system operators – where wholesale electricity rates and ancillary services exist – are not where most batteries are earning their revenue these days.

LBNL said that by the end of 2020, most operating hybrids earned revenue via incentive programs or capacity and transmission demand charge markets, instead of wholesale market price signals.

For instance, a battery used for peak shaving behind the meter at a business, or to maximize onsite solar utilization, does little for the broader wholesale market – although they do offer some general peak demand reduction. A battery at a home only running during power outages offers far less than a peak shaving solution; however, some VPPs are beginning to step into this space to monetize these underutilized resources.

We’re also observing a separation of attachment rates, as residential solar-plus-storage is growing faster than small business, commercial, and industrial. LBNL has also observed that residential energy storage solutions are getting larger.

This split – where residential storage is surpassing commercial and industrial storage – is mirrored by residential solar as well, as it outpaces business, commercial, and industrial solar in terms of capacity deployed annually.

Author: John Fitzgerald Weaver

China aims to build 450 GW of solar, wind power on Gobi desert

The construction of about 100 GW of solar power capacity is already under way in the desert area. Image: Reuters

From The Straits Times

BEIJING (REUTERS) – China plans to build 450 gigawatts (GW) of solar and wind power generation capacity on the Gobi and other desert regions, the chief of the state planner said on Saturday, as part of efforts to boost renewable power use to meet climate change goals.

President Xi Jinping has pledged to bring China’s total wind and solar capacity to at least 1,200 GW and to cap its carbon emission to a peak by 2030.

“China is going to build the biggest scale of solar and wind power generation capacity on the Gobi and desert in history, at 450 GW,” Mr He Lifeng, director of the National Development and Reform Commision (NDRC), said on the sidelines of the National People’s Congress.

China had installed 306 GW of solar power capacity and 328 GW wind capacity by the end of 2021.

The construction of about 100 GW of solar power capacity is already under way in the desert area.

Mr He also acknowledged that high-efficient coal-fired power plants and ultra-high voltage electricity transmission lines are required in order to support the steady operation of the grid system amid large scale of renewable power installation.

Coal-fired power utilities can generate a stable baseload power supply to renewables, which can fluctuate with weather conditions.

He’s comment echoed a statement from China’s Vice Premiere Han Zheng this week that China should give full play to “coal’s basic guaranteeing role in energy supplies”.

The NDRC said in its 2022 work plan issued on Saturday that China will “continue to leverage the peak-shaving and basic supporting role of traditional energy, especially coal and coal-fired power.”