> ## Documentation Index
> Fetch the complete documentation index at: https://docs.voltview.co.uk/llms.txt
> Use this file to discover all available pages before exploring further.
# Demand and capacity
> Maximum demand, MIC, load factor, and why a portfolio peak is smaller than the sum of site peaks.
Energy (kWh) says how much a site used. **Demand** says how hard it pulled, and **capacity** is what it is allowed to pull. Those are the numbers behind peak-demand endpoints and the capacity line on a C\&I bill.
## Billing terms
| Term | Meaning | Where it shows up |
| --------------------------------- | --------------------------------------------------------- | ------------------------------------------------------- |
| **Connected load** | Nameplate rating of everything installed (kW or kVA) | Design / commissioning, not the bill |
| **Maximum demand** | Highest *average* demand in any one interval in the month | Peak-demand APIs; sometimes a billed MD |
| **Maximum import capacity (MIC)** | Capacity agreed with the DNO / IDNO, planned in **kVA** | Invoice `maximumImportCapacity`, capacity charge |
| **Demand factor** | Maximum demand ÷ connected load | Always ≤ 1. The site never runs every nameplate at once |
| **Load factor** | Average demand ÷ maximum demand, as a percentage | Peak-demand `loadFactor` |
UK settlement intervals are usually **30 minutes**. Maximum demand is therefore the highest half-hour average, not a single-cycle spike. Some meters can be set to 15 or 60 minutes; do not mix interval lengths when you compare sites.
MIC is a **contract**. Maximum demand is a **measurement**. A site can breach MIC (and pay excess capacity) without changing the contracted figure. VoltView reports both; it does not treat peak kW as a kVA capacity.
## What VoltView returns
The peak-demand endpoints give you:
| Field | Unit | Meaning |
| --------------- | -------- | ------------------------------------------------------------ |
| `peak` | kW | Highest average power in an interval in the requested window |
| `timestamp` | ISO 8601 | When that interval started |
| `averageDemand` | kW | Mean power over the same window |
| `loadFactor` | % | `averageDemand ÷ peak` |
A high load factor means the site is using its peak steadily (process, refrigeration, always-on). A low load factor means a short spike and a lot of idle capacity — the usual case for offices, kitchens, and EV chargers.
Capacity on the contract is still in **kVA**. Convert only when you have power factor:
```
peak kVA ≈ peak kW / power factor
```
If you do not have kvarh or kVAh for that interval, leave the comparison in kW and do not invent a PF. See [Energy and power](/metering/energy-and-power).
## Diversity (ADMD)
Individual site peaks do not happen at the same minute. **Diversity factor** is:
```
sum of individual maximum demands ÷ coincident maximum demand of the group
```
It is usually greater than 1. The coincident peak of ten shops is smaller than the sum of their ten peaks.
**After Diversity Maximum Demand (ADMD)** is that coincident figure: what you size a feeder, a transformer, or a portfolio view for.
Worked example — four buildings on one landlord supply:
| Site | Connected load | Demand factor | Site maximum demand |
| ---------------- | -------------- | ------------- | ------------------- |
| Retail | 180 kVA | 0.70 | 126 kVA |
| Office | 250 kVA | 0.55 | 137.5 kVA |
| Cold store | 320 kVA | 0.85 | 272 kVA |
| Workshop | 90 kVA | 0.60 | 54 kVA |
| **Sum of peaks** | | | **589.5 kVA** |
If the four peaks are not coincident and diversity is 1.4:
```
ADMD = 589.5 ÷ 1.4 ≈ 421 kVA
```
The incoming capacity can be planned around \~400–450 kVA, not 600 kVA. At diversity 1.0 you would have to size for the full 589.5 kVA.
The same idea applies inside one site: lighting, HVAC, and process lines rarely peak together. That is why connected load is a poor proxy for MIC, and why a portfolio "sum of site peaks" overstates the grid-level peak.
Peak demand for **all sites** in the API is per-site, then listed. It is not an ADMD. Adding the `peak` values together is the diversity = 1.0 case — useful as an upper bound, not as the coincident portfolio peak.
## How this hits the bill
Capacity is charged on the contracted MIC, in p/kVA/day, for every day of the period. It does not fall just because a quiet month had a low maximum demand.
What *does* move the bill:
| If this is true | Typical effect |
| ---------------------------------- | -------------------------------------------------------------------------------------------------------------- |
| Measured peak stays well below MIC | You may be paying for unused capacity — a procurement / DNO conversation |
| Measured peak exceeds MIC | Excess capacity charges; the DNO can also require a capacity increase |
| Power factor is poor at the peak | The same kW needs more kVA; you eat MIC faster and may pick up kvarh charges |
| A battery covers the peak interval | Import peak falls; the battery must actually discharge in *that* half-hour. See [Batteries](/assets/batteries) |
## What we do not do
* Treat `peak` (kW) as MIC (kVA).
* Collapse a portfolio to one ADMD unless you have asked for a coincident series, not a sum of site peaks.
* Size a transformer or a DNO application from VoltView alone. Use these figures as the measured input to that conversation.