The World's #1 Renewable Energy Network for News, Information, and Companies.
Untitled Document

Solar Intermittency: How Big is the Problem?

Intermittency is one of the major criticisms of solar — the majority of the energy is delivered when the sun is shining brightly, but virtually none is created at night or in substantial cloud cover.

How do solar developers view this issue — does it pose a huge stumbling block to current projects, or is it something that has been effectively managed? I spoke with two gentlemen, Martin Hermann, CEO of 8minutenergy Renewables and Paul Copleman, communications manager at Iberdrola Renewables, to find out more. 

Are there specific technologies used to deal with intermittency? Surprisingly, neither developer implements storage technologies on-site because there is no need to do so.

In fact, it seems that solar technology has already occupied a niche where it can thrive without a storage solution. 

Copleman explains, “[the] integration of significant amounts of intermittent generation is entirely feasible with the existing grid,” due to the “ability of the grid to respond to changes in generation levels in real time using the existing generation and transmission system.” Thus, on the supply side, the technology is feasible, and solar can fit into a niche market. “Solar PV’s production curve is aligned with the peak demand during the day and therefore helps to shave the peaks within a utility’s generation profile,” said Hermann.

In fact, even without storage technology, the PV intermittency seems to be effectively managed at current project scales. Mr. Copleman stresses the distinction between intermittency and predictability: “It’s important to understand that while solar is intermittent, it does not have a random generation pattern. Solar resource is very predictable, which makes grid integration less of an issue. Additionally, forecasting solar resource on a day-ahead and hour-ahead basis has a high accuracy factor.”

Besides having a predictable generation pattern, other measures are being used to tackle the problem. For example, Iberdrola is “evaluating its wind projects for where a co-located and co-interconnected solar project would increase capacity factor as well as decrease sub-hourly intermittency.” Also, project screening avoids locations where intermittency becomes a substantial issue for the system. 

While both gentlemen state that intermittent power is not a short-term problem, they agree that it would become an issue in the longer term. This would happen when solar finally moves from its current niche as a supplemental resource and transitions to become a firm, baseload resource. “Locating 1,000 MW of PV on one transmission line will clearly be more difficult to integrate than 1,000 MW of PV spread across multiple distribution and transmission lines and across a broader geographical area,” said Copleman.

Current researchers and developers of storage solutions should pay attention to two different milestones that would be game-changers in the way solar energy is utilized today. The first milestone, at three to five hours of storage, “will allow a precise overlap between the PV production curve and the demand peak of a particular utility,” said Hermann. “The second milestone, at 20 hours of storage, will enable PV to work as a base load resource.”  

Both solutions must be cost-effective though, as they will compete directly with traditional base load resources like LNG and coal. Once these milestones are reached, solar energy is set to transform the world in a much greater way.

Untitled Document


Sunrise in Pakistan as the Country Delves into Solar PV

Robert Harker Pakistan has joined the list of countries that are exploring solar power as a means to bridge critical energy generat...

Global Renewable Energy Roundup: China, Kenya, Turkey, India Seeking More Renewables

Bloomberg News Editors China is being encouraged by three industry groups to double the nation’s solar-power goal for 2020 to make up for sh...

Why Smarter Grids Demand Smarter Communications Networks

Mark Madden

Historically, utility networks and communications networks have had little in common.

The Importance of “Switching Costs” to the US Residential Solar Industry

Paula Mints The DoE and numerous organizations and governments globally are focused on driving down the cost of solar convinced t...


Intersolar AWARD „Solar Projects in India“ – Applications being accepted until September 18

The Intersolar AWARD in the category Solar Projects in India honors projects in the fie...

OFS Announces Commercial Availability of InvisiLight® MDU Optical Solution for Multiple Dwelling Units

OFS, a leading-edge designer, manufacturer and supplier of innovative fiber optic netwo...

New local energy partnership brings innovative solar tracker to Washington State

A new partnership will bring the innovative AllEarth Solar Tracker solar electric syste...

30 days to GRC Annual Meeting & GEA Geothermal Energy Expo

The Geothermal Resources Council (GRC) has announced that it is only 30 days to go to t...


Cronimet / THEnergy study: In solar for mines size does not always matter - Reducing CAPEX with energy efficiency and load shifting

Munich, September 2015. Mining companies are constantly gaining interest in solar solutions because frequently solar ...

Final Program Now Available for GRC Annual Meeting & GEA Geothermal Energy Expo

GRC Annual Meeting & GEA Geothermal Energy Expo - Final Program from

Vacancy? No Problem!

Have you ever tried to sell an efficiency product or service to a prospect that owns or manages a building with high ...

Shedding Some Light on a Taxing Situation for Community-Shared Solar

For renters and for property owners with inadequate roof space, the many benefits of solar electricity may seem out o...


Siah Hong Tan is a research specialist in Singapore. He is currently performing research on material systems that might be able to convert sunlight directly into fuels like hydrogen or methanol, thus addressing the issue of enabling long term, lar...


Volume 18, Issue 4


To register for our free
e-Newsletters, subscribe today:


Tweet the Editors! @jennrunyon



Doing Business in South Africa – in partnership with GWEC, the Glob...

Wind Energy in South Africa has been expanding dramatically, growing fro...

Intersolar India 2015

Exhibition and Conference: November 18-20, 2015 Intersolar India 2015 I...

Intersolar North America 2016

Exhibition: July 12 - 14, 2016; Conference: July 11 - 13, 2016 Intersola...


Less Is More

When you’re giving a presentation, one of the easiest things to do...


One of the biggest challenges we face as efficiency sales professionals ...

How To Optimize Your Meeting Schedule

Do you spend more time in meetings than you do actually working? While m...


Renewable Energy: Subscribe Now

Solar Energy: Subscribe Now

Wind Energy: Subscribe Now

Geothermal Energy: Subscribe Now

Bioenergy: Subscribe Now