| vatPercent | Percentage of the value added tax to apply to net prices. Optional, defaults to 19. |
| basePrice | The net(!) base price you have to pay for every kWh. Optional, but you most probably want to set it based on you delivery contract. |
| timeZone | The time zone the hour definitions of the things below refer to. Default is `CET`, as it corresponds to the aWATTar API. It is strongly recommended not to change this. However, if you do so, be aware that the prices delivered by the API will not cover a whole calendar day in this timezone. **Advanced** |
| country | The country prices should be received for. Use `DE` for Germany or `AT` for Austria. `DE` is the default. |
| rangeStart | First hour of the time range the binding should search for the best prices. Default: `0` |
| rangeDuration | The duration of the time range the binding should search for best prices. Default: `24` |
| length | number of best price hours to find within the range. This value has to be at least `1` and below `rangeDuration` Default: `1` |
| consecutive | if `true`, the thing identifies the cheapest consecutive range of `length` hours within the lookup range. Otherwise, the thing contains the cheapest `length` hours within the lookup range. Default: `true` |
#### Limitations
The channels of a bestprice thing are only defined when the binding has enough data to compute them.
The thing is recomputed after the end of the candidate time range for the next day, but only as soon as data for the next day is available from the aWATTar API, which is around 14:00.
So for a bestprice thing with `[ rangeStart=5, rangeDuration=5 ]` all channels will be undefined from 10:00 to 14:00.
Also, due to the time the aWATTar API delivers the data for the next day, it doesn't make sense to define a thing with `[ rangeStart=12, rangeDuration=20 ]` as the binding will be able to compute the channels only after 14:00.
## Channels
### Prices Thing
For every hour, the `prices` thing provides the following prices:
| market-net | Number | This net market price per kWh. This is directly taken from the price the aWATTar API delivers. |
| market-gross | Number | The market price including VAT, using the defined VAT percentage. |
| total-net | Number | Sum of net market price and configured base price |
| total-gross | Number | Sum of market and base price with VAT applied. Most probably this is the final price you will have to pay for one kWh in a certain hour |
All prices are available in each of the following channel groups:
| channel group | description |
|----------|--------------------------------|
| current | The prices for the current hour |
| today00, today01, today02 ... today23 | Hourly prices for today. `today00` provides the price from 0:00 to 1:00, `today01` from 1:00 to 02:00 and so on. As long as the API is working, this data should always be available |
| tomorrow00, tomorrow01, ... tomorrow23 | Hourly prices for the next day. They should be available starting at 14:00. |
| active | Switch | `ON` if the current time is within the bestprice period, `OFF` otherwise. If `consecutive` was set to `false`, this channel may change between `ON` and `OFF` multiple times within the bestprice period. |
| start | DateTime | The exact start time of the bestprice range. If `consecutive` was `false`, it is the start time of the first hour found. |
| end | DateTime | The exact end time of the bestprice range. If `consecutive` was `false`, it is the end time of the last hour found. |
| countdown | Number:Time | The time in minutes until start of the bestprice range. If start time passed. the channel will be set to `UNDEFINED` until the values for the next day are available. |
| remaining | Number:Time | The time in minutes until end of the bestprice range. If start time passed. the channel will be set to `UNDEFINED` until the values for the next day are available. |
| hours | String | A comma separated list of hours this bestprice period contains. |
The idea of this binding is to support both automated and non automated components of your home.
For automated components, just decide when and how long you want to power them on and use the `active` switch of the bestprice thing to do so.
Many non automated components still allow some kind of locally programmed start and end times, e.g. washing machines or dishwashers.
So if you know your dishwasher needs less than 3 hour for one run and you want it to be done the next morning, use either the `countdown` or the `remaining` channel of a bestprice thing to determine the best start or end time to select.
