Twelve professional tools for solar sizing, electrical load analysis, voltage drop, generator and battery selection, bund wall containment, A/C and water systems, and hurricane preparedness — built for Caribbean codes, climate, and costs. Free, no signup.
Every tool runs in your browser, works on your phone, saves calculation history, produces printable reports, and links into the next step of your design — from a JPS bill all the way to a wired, backed-up system.
Yes. All 12 calculators are completely free with no signup, no trial limits, and no watermarked reports. WattWorks Design offers paid professional design services if you need a stamped, site-specific design.
The tools use recognized methods - NEC tables for electrical sizing, EPA 40 CFR 112 rules for containment, standard load factors for HVAC and water. They are preliminary design tools: excellent for scoping, budgeting, and sanity-checking, but final designs should be verified by a licensed engineer for your specific site.
Yes. The voltage drop calculator uses the circular-mil method with NEC 310.16 ampacity checks, the conduit fill calculator follows NEC Chapter 9 Tables 1, 4, and 5, and the load calculator applies NEC demand factors.
With JPS rates among the highest in the region and 4.7-5.8 peak sun hours, typical residential payback is 4-7 years. Use the Energy Bill Savings calculator to get a projection from your actual monthly bill in about 30 seconds.
It sizes secondary containment to EPA 40 CFR 112 (SPCC): 110% of the largest tank or the sum of all tanks, accounting for tank displacement, wall thickness, working clearances, and freeboard - with 2D diagrams and an interactive 3D model of the design.
Every calculator has a Share button that copies a link reproducing your exact inputs, plus automatic calculation history on your device and printable PDF-ready reports.
Yes. Everything is mobile-first and the site works offline after your first visit thanks to progressive web app caching - useful on job sites with poor signal.
A bund wall is a secondary containment structure designed to prevent environmental contamination from fuel storage tank spills or leaks. Required by EPA regulations for facilities storing petroleum products, bund walls must contain at least 110% of the largest tank's volume.
Learn more about regulations →The Spill Prevention, Control, and Countermeasure (SPCC) rule requires facilities with oil storage capacity above 1,320 gallons to have secondary containment. Our calculator ensures compliance with 40 CFR 112.8(c)(2) requirements.
View EPA regulations →Effective bund wall design accounts for tank displacement, wall thickness, working clearances, and freeboard for rainfall. Industry practice limits bund height to 1.5 meters for safety access. Consider drainage, leak detection, and maintenance access in your design.
Start designing →Caribbean nations including Jamaica often adopt EPA standards or equivalent regulations. Our tools are specifically designed for Caribbean engineers, supporting both imperial and metric units. Always verify with local authorities like Jamaica's NEPA for specific requirements.
Visit Jamaica NEPA →Net containment volume equals gross bund volume minus tank displacement. Our calculator uses iterative refinement to account for height-dependent effects, achieving accuracy within 0.001 cubic feet. Tank footprint and plinth volumes are properly accounted for.
View calculation method →Beyond EPA requirements, NFPA 30 provides guidance on flammable liquid storage including minimum tank spacing (3 feet), fire protection, and ventilation. UK HSE and API standards also provide valuable guidance for international projects.
NFPA 30 standards →Caribbean locations receive 4.7–5.8 peak sun hours (PSH) daily, making solar especially attractive. With electricity rates among the highest globally, typical payback periods are 4–7 years. Our solar calculator uses location-specific PSH and rates for accurate system sizing and financial analysis.
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