22.5.2026
FAQs: How Delta Link Connection Works
Reliable connectivity to your customers' assets is the foundation of residential flexibility. The moment grid imbalance spikes, you need a fast, stable connection to every household in your portfolio. Every second of delay translates directly into lost revenue.
We know this decision well, because we had to make it ourselves. Delta Green started as a software company. We're a small electricity retailer with a portfolio of 7,000+ homes, and like many of you, we never wanted to deal with hardware. So before building anything, we tested every cloud-to-cloud API we could find.
What we discovered: none of them were suitable for flexibility at the level the market actually demands. The data latency was too high, the granularity too coarse, and the control too limited for real-time dispatch, let alone access to markets like aFRR. Cloud-to-cloud is convenient. It's just not enough.
We also looked at gateway devices already on the market. Most required a professional installer visit. That alone kills the business case for residential-scale rollout.
So we built our own. Not because we were excited about shipping hardware (we weren’t), but because the math was clear. A gateway was necessary. The question was just whether it could be small, self-installable, and cheap enough to justify. We concluded it could.
That's Delta Link: a small box your customer receives in the mail and plugs into their home Wi-Fi. No technician. No friction.
We've already written about why Delta Link outperforms cloud-to-cloud connectivity. Here, we'll walk you through how straightforward the distribution and onboarding actually is.
What does Delta Link look like and what does it cost?
Delta Link is roughly the size of a chocolate square. It arrives in a branded box made from sustainable materials with a mycelium insert. Compact, but thoughtfully packaged.
The device costs €20 one time. No recurring fees, no subscription charges, no hidden costs for the customer.
Now compare that to the API route. Today, most PV inverter APIs are free, and EV APIs cost a few euros per device per month. Sounds manageable. But ask yourself: do you expect that to stay the same?
We don't. And neither does the industry. No one we've spoken to has ever seriously argued otherwise. For PV specifically, we're already seeing pricing models being introduced that are due to roll out soon. The manufacturers who built those APIs didn't do it out of goodwill. At some point, they will monetise them.
Read the full article
No technician. No subscription. No complexity. Customers plug it in themselves. You're ready to trade within weeks. This guide walks through how Delta Link works, what customers experience, and which markets you can reach from day one.