Renewable heat production providing energy to existing heat consuming systems do not need storage. A heat exchanger is sufficient.
In a perfect world all fossil fuels will be replaced by renewables. However, as discussed in my opening article An Opportunity As Big As Electricity & Transportation Combined, due to the overall increase in global energy demand, the use of fossil fuels is expected to be continuously increasing for the next several decades even though renewables take up a still larger market share.
Taking advantage of the relatively low costs of long-duration heat storage is one way to further increase renewables share of the energy market. This opportunity can be boosted tremendously if government-funded research programs and investors direct more funds towards development and commercialization of low-cost, high-temperature storage solutions.
In the meantime combining renewables and fossil fuels will get us far. This is a straight-forward procedure where a standard heat exchanger and simple control systems can do the job.
An example of this is how a solar field integrates with fossil-fired sources by transferring the produced heat to the user's heat system via a heat exchanger: When the solar field is in operation the user turns down heat production from its existing heat delivery system (typically a gas burner). When cloudy and/or at night the existing heat delivery system works as it has always done. The illustration above shows a Heliac solar field delivering the heat, but this could just as well be any other type of solar field, a biomass burner, or heat from a waste heat source.
'Oversized' solar fields allow for extra production to charge heat storages. As discussed in my previous article a simple hot water tank can do the trick as long as the stored heat is below 100C/212F. For higher temperatures storage solutions based on molten salts, rocks, concrete, and heated oils are among the available options.
Consulting engineers already experts in system integration design can deal with all the practical elements of integrating solar fields to specific use cases. This allows companies like Heliac to standardize solutions and consequently also enjoy scale economies from standardized procedures and mass-produced components.
With standardization follows faster acceptance from authorities, faster delivery and installation, and lower cost of capital from banks. With economies of scale come lower prices to the benefit of the users, their customers, and ultimately the climate.
Almost endless opportunities present themselves to solutions that can benefit from scale and standardization as also shown in Cost of Heat. However, to get scale a few significant challenges need be overcome. This is the subject of 'The Credibility Challenge' which will publish in a few weeks.
But first I'll take a look at the physical footprint of solar fields: Is the necessary space available for utility-scale solutions and do we need rooftop solar thermal for industries? That's up next.
Interested in reading more? Please see the links to my other articles below. Additionally, a 'Like’ from you will also be much appreciated as this should help direct more attention at the many business and climate opportunities the market for heat production offers.
Thank you for reading,
I have spent the better part of 20 years investing in cleantech startups. During my career I have probably seen at least 3,000 business proposals, including Heliac's which I was introduced to in 2016 when I headed Climate-KIC Nordic's accelerator program. I found -and still find - Heliac's solution to be by far the best new solution I've ever come around, which is why I joined the company in early 2017.
Disclaimer: I have not double-checked all my sources and I am not an expert in all areas mentioned in the articles. I may therefore have reached conclusions that wiser men and women may know to be inaccurate. If so, I trust they will let me know, so I can become a bit wiser too.