# Discover How to Cut Fuel Costs & Emissions with Solar Thermal Solutions with Don Frank

> Think your boiler is efficient? It’s probably your biggest hidden cost. This short call breaks down how solar thermal slashes fuel bills by up to 80%—without replacing your system. We’ll show real-world savings, feasibility insights, how it works and various case studies. If you're running on steam or have large hot water applications, this is worth a conversation.

- Host: Don Frank
- Duration: 45, 60 min
- Location: Zoom Video
- Host time zone: America/Indianapolis
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/don-frank/solarthermalsolutions
- Event type id: 2162689

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=2162689&start=YYYY-MM-DD&end=YYYY-MM-DD&timeZone=<IANA time zone>
cal-api-version: 2024-09-04
```

The response is `{"data":{"YYYY-MM-DD":[{"start":"<ISO 8601 with offset>"}]}}`; no API key is needed.

## Book

```http
POST https://api.cal.com/v2/bookings
cal-api-version: 2026-02-25
Content-Type: application/json

{
  "eventTypeId": 2162689,
  "start": "<UTC ISO 8601 start from the slots response>",
  "lengthInMinutes": 45,
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "guests": [
    "guest@example.com"
  ],
  "bookingFieldsResponses": {
    "notes": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address)
- Optional fields: `notes` (Additional notes), `guests` (Add guests)
- `name` and `email` go in `attendee` and `guests` is a list of emails; every other field goes in `bookingFieldsResponses` under its name.
- `lengthInMinutes` picks one of 45, 60; pass the same value to the slots request as `duration`.