Dive Brief:

• Financial activity for the storage, efficiency, and smart grid sectors was lower overall during Q3 2015 than the previous quarter, but the overall size of the deals grew, according to Mercom Capital Group's Q3 2015 funding and mergers and acquisitions report for those sectors. 
• Venture capital funding for energy efficiency and smart grid technology startups in the year-to-date has increased over the same period last year, according to Mercom. Meanwhile, VC funding for energy storage in the year-to-date has fallen over the past year. 

Dive Insight:

Despite many analysts' bullish projections for the future of energy storage, venture capital isn't flowing to the sector as fast as you might expect. 

In contrast, VC funding numbers are growing for efficiency and smart grid companies while energy storage companies saw their figures fall from $383 million raised through the first three quarters last year to $290 million raised through the same period this year.

Of all the sectors, efficiency is attracting the most capital. Through the year so far, efficiency companies raised $667 million, compared to $604 million last year.

Smart grid companies are seeing a similar amount of VC funding as the storage sector: Smart grid companies raised $370 million during Q3 this year, compared to $325 million last year.

But there's reason for the U.S. storage industry to remain positive about the news, despite the dip in overall funding. The U.S. made up "nearly all" of the financial activity in energy storage, according to Mercom, with $94 million of the total $96 million raised during Q3 2015 coming from the U.S. 

While those numbers are actually a decrease from Q2 this year, it's important to note that the deal size increased during Q3, and much of the Q2 number came from one large deal. 

Out of the latest Q3 numbers, the biggest deal was RWE's $33 million investment in battery storage provider Stem. The battery company is focused on deploying storage to commercial and industrial customers, but it has made waves recently by aggregating behind-the-meter storage at the residential level and deploying it into the California ISO's real-time market as a demand response resource. This was the first time storage was leveraged in this way in California. 

The other big storage deals from the last quarter were a $25 million raise by Primus Power, a $12.3 million raise by Greensmith, a $10 million raise by Advanced Microgrid Solutions, and a $6.6 million raise by SolidEnergy.