St James solar guide

The Montego Bay coast outperforms much of the interior.

St James combines dense coastal development with steep inland communities. The parish mean is useful, but the map and the roof-access questions explain more than one headline number.

Local data guide · published 31 August 2026

Try a system size

What would that mean on a roof?

These figures estimate electricity from the panels, not money saved. A kWh is one unit of electricity on your bill; kW describes the panel system’s rated size. Your savings depend on when you use that electricity, whether you store it in a battery and whether you send any to JPS Jamaica.

Typical year

7,865 kWhabout 655 kWh per month on average

Middle half of locations

7,709–7,948 kWhDifferences between locations; your roof can change the result

Strongest month

March · 736 kWhLong-term average, not a forecast

Weakest month

June · 628 kWhAbout 15% below March

Colour map of modelled annual solar electricity output across St James. — **Annual solar electricity across St James**Each square is approximately 1 km. The stepped edge shows the source resolution rather than pretending the estimate is more precise.

About 1,470About 1,680 kWh/kWp

The parish is not one number

The northern coastal belt is strongest. Inland hills are more moderate.

The highest cells sit along the north coast around the wider Montego Bay area. Output generally softens inland toward higher terrain around Anchovy, Cambridge and the parish interior.

Urban shade, multi-storey access and coastal corrosion can therefore matter at least as much as the mapped solar difference.

Cells analysed: 745
Central geographic range: 1,542–1,590
Typical variation: About ±2%

Month by month

How does solar output change through the year?

March is strongest in the long-term model. June produces about 85% of that output, so the annual figure should not be treated as twelve identical months.

645Jan

641Feb

736Mar

689Apr

648May

628Jun

661Jul

666Aug

645Sep

649Oct

628Nov

629Dec

Estimated monthly generation in kWh for the selected system size. Hover, tap or focus a bar for its detailed value. The figures are long-term estimates, not a weather forecast.

View the monthly figures as a table

Month	Per installed kW	5 kW system
January	128.9 kWh	645 kWh
February	128.2 kWh	641 kWh
March	147.2 kWh	736 kWh
April	137.7 kWh	689 kWh
May	129.6 kWh	648 kWh
June	125.6 kWh	628 kWh
July	132.2 kWh	661 kWh
August	133.3 kWh	666 kWh
September	129.0 kWh	645 kWh
October	129.9 kWh	649 kWh
November	125.6 kWh	628 kWh
December	125.9 kWh	629 kWh

Before asking for quotes

Questions worth asking in St James.

What shades the roof in the city?Neighbouring buildings, water tanks, telecoms equipment and trees can produce hard-edged shade that a parish map cannot see.
How will equipment reach the roof?Multi-storey and tightly developed sites need a realistic lifting, scaffolding and fall-protection plan before the quote is treated as final.
Is the hardware right for coastal air?Near the Montego Bay coast, confirm module salt-mist testing, compatible fasteners, enclosure ratings and warranty conditions.
Will the system serve daytime use?Air-conditioning and home-business loads can improve self-use, but the proposal should model the customer’s actual schedule rather than assume it.

Use the Jamaica panel and roof guide to test the mounting and equipment answers in a quotation.

Generation is not the bill

A 5 kW system making 655 kWh a month will not automatically erase the same-sized bill.

Timing decides value

Solar used in the home avoids the retail cost of a JPS Jamaica unit. Surplus sent through net billing receives a much lower export credit.

A battery moves energy

A battery can carry daytime generation into evening use and provide outage cover, but it does not make the panels generate more.

Your roof changes the result

Shade, direction, heat, dirt, cable losses and equipment choices move a real installation away from the parish benchmark. Use the panel guide to test those roof assumptions.

How we calculated this

Where do these estimates come from?

We use long-term sunshine data to estimate panel output across the parish. These are planning averages, not a forecast for your roof. Shade, roof direction and equipment can change the result.

See the data, calculation and source assumptions

We selected the 745 Global Solar Atlas PVOUT grid cells whose centres fall inside the St James parish boundary, then calculated the annual mean, central 50% range and monthly means.

The source models a free-standing crystalline-silicon system at optimum fixed tilt. It is useful for parish comparison and early planning, not a guarantee for a particular roof.

Solar source: Global Solar Atlas 2.0 PVOUT
Source years: 1999–2018 long-term average
Spatial resolution: 30 arc-seconds, approximately 1 km
Calculation: Jamaica Solar Check parish aggregation

Solar data obtained from Global Solar Atlas 2.0, developed and operated by Solargis on behalf of the World Bank Group with ESMAP funding. Source data © 2019 Solargis, CC BY 4.0. Parish calculations and colour map are adaptations by Jamaica Solar Check; the source organisations do not endorse this site. Boundary geometry: geoBoundaries JAM ADM1, sourced from OpenStreetMap/Wambacher, CC BY-SA 2.0.