Technology / Solar Integration
Solar-Powered ERD — Run Your Lift on Sunlight
Su-vastika’s patented solar integration adds photovoltaic generation as a third power source alongside grid and battery. The MPPT controller maximises solar energy harvest while the bi-directional architecture manages all three sources seamlessly — with zero switching delays and full IGBT-quality output.
Why Solar + ERD Makes Engineering Sense
A lift is one of the best-suited loads in a building for solar integration. Its energy consumption is high (typically the second-largest consumer in a residential building after HVAC), predictable (usage peaks follow daily routines), and partially recoverable (regenerative braking during descent).
An ERD already contains the power conversion hardware needed to interface with solar panels — a DC bus, IGBT switching, and battery management. Adding an MPPT controller and solar input stage requires relatively modest incremental hardware. The result is a system where solar panels charge the battery during the day, and the battery supplies the lift during the evening and during grid failures — reducing electricity consumption and providing power resilience simultaneously.
In locations with 5–7 peak sun hours per day (typical across Haryana, Rajasthan, Gujarat, and most of peninsular India), a properly sized solar array can cover 40–70% of a lift’s daily energy consumption.
MPPT: Maximum Power Point Tracking
A solar panel’s maximum power output depends on the voltage at which it operates. This "maximum power point" shifts with temperature, irradiance, and panel age. Without active tracking, a fixed-voltage controller wastes 15–30% of available solar energy.
An MPPT (Maximum Power Point Tracker) continuously adjusts the panel operating voltage to keep it at the maximum power point. It acts as a DC-DC converter — taking the variable panel voltage and converting it to the ERD’s fixed DC bus voltage. Modern MPPT controllers achieve 95–98% conversion efficiency.
Three-Source Power Architecture
The patented solar ERD architecture manages three simultaneous power sources with a hierarchy:
Solar energy is used first — it has zero marginal cost. When solar output exceeds lift motor demand, the excess charges the battery.
If solar generation is below lift demand (cloud cover, evening), battery supplements. If grid is available, battery also charges simultaneously from solar + grid.
Grid power supplements solar to ensure battery stays topped up. If grid and solar both fail, battery alone supports the lift until depleted.
The IGBT output to the motor is always maintained regardless of which source combination is active. The motor sees identical pure sine wave output in all configurations — there is no quality or reliability difference from the motor’s perspective.
HAREDA Mandate — Solar ERD Now Required in Haryana
The Haryana Renewable Energy Development Agency (HAREDA) has mandated solar-capable ERDs for all new lift installations in Haryana. This is part of the state’s broader solar adoption policy for commercial and residential buildings.
For lift manufacturers and installers operating in Haryana, a standard ERD without solar input capability is no longer compliant for new installations. Buildings with existing ARD systems replacing them with ERDs are also encouraged to install the solar-enabled variant.
The mandate covers the Haryana Lifts and Escalators Act and associated HAREDA building codes. Non-compliance affects occupancy certificates for new constructions.
Sizing a Solar ERD Installation
Solar panel sizing depends on three inputs: daily lift energy consumption (kWh), available roof/shade-free area, and local peak sun hours. A rough guideline for Haryana/North India installations:
| ERD Size | Typical Lift | Est. Daily Energy | Solar Panel Recommendation | Area Required |
|---|---|---|---|---|
| 10 kVA | 630kg, 1m/s residential | 3–5 kWh/day | 1.5–2 kWp | 8–10 m² |
| 15 kVA | 1000kg, 1.5m/s mid-rise | 6–9 kWh/day | 2.5–3.5 kWp | 14–18 m² |
| 20 kVA | 1250kg, 1.75m/s commercial | 9–14 kWh/day | 4–5 kWp | 22–28 m² |
| 30 kVA | 1600kg, 2.5m/s high-rise | 14–22 kWh/day | 6–8 kWp | 32–42 m² |
Estimates based on 5.5 peak sun hours/day (North India average). Actual consumption varies with lift usage frequency.
For exact ERD KVA sizing based on your lift specifications, use the LiftInverter.com ERD Calculator. For solar panel sizing consultation, contact Su-vastika directly — their engineering team provides installation surveys and system design.
Find Your ERD KVA First
Solar panel sizing starts with the ERD KVA rating, which is based on your motor power and lift specifications. Calculate it here.