Source
doi:10.1590/s1678-86212018000100230 — original publication (opens in a new tab; the file is not redistributed)
Summary
Marinoski & Ghisi (2018) assess the environmental (LCA) and economic feasibility of household rainwater harvesting for a 61.3 m² low-income house in Florianópolis, Brazil, where roof water supplies toilet flushing (~30% of demand). A 4.0 m³ tank substitutes 27.71% of potable demand. The study’s distinctive contribution is comparing three storage-tank materials — glass-fibre-reinforced plastic, HDPE, and reinforced concrete — on embodied energy, CO2, cost and payback. It finds that the storage tank dominates the system’s embodied energy and emissions, and that the environmentally-best material (GRP) is not the economically-best (concrete): concrete is cheapest with the only viable payback (14.5 yr), but carries the highest embodied energy and CO2. It also shows that adding any RWHS system raises embodied energy and CO2 above a no-system baseline — the net environmental case depends on lifetime water savings. For Neobiome Intelligence this is a directional design input for the rainwater-harvesting technology (tank-material selection as an embodied-carbon ↔ cost ↔ payback trade-off), complementing the NZ-specific cost/yield data already on the tech page.
Key claims
See key_claims frontmatter (6 claims, all cited to source location).
Neobiome Intelligence relevance
- Tank material is a real design trade-off (D03 / rainwater_harvesting). For a community rainwater system, the storage tank dominates both embodied carbon and cost, and the two pull in opposite directions: glass-fibre-reinforced plastic minimises embodied energy/CO2, while reinforced concrete minimises cost and payback. NI’s rainwater sizing should expose this choice rather than assume one material LIT_051.
- RWHS is not environmentally free. Every rainwater variant had higher embodied energy and CO2 than the potable-only baseline; the environmental benefit is earned only through operational water savings over the tank’s life — a caveat NI should carry when claiming a rainwater system is “sustainable” LIT_051.
- Payback is tariff- and demand-sensitive. The 14.5–32.7-year paybacks reflect low Brazilian water tariffs; viability improves with higher tariffs or a larger non-potable demand fraction — so NZ payback (higher tariffs, see CR_016) is likely shorter, and the NI payback calc should be tariff-driven, not transferred.
- ⚠ Scope. Brazil, single low-income house, toilet-flushing-only non-potable use, ~1,595 mm/yr. Transfers as method + directional finding. NZ cost/yield, consent thresholds and dual-reticulation specifics are held on rainwater_harvesting (OT_039, CR_016, int_006).
Research targets
Research gaps
- NZ-context embodied-carbon comparison of community rainwater storage materials (HDPE vs concrete vs GRP at the tank sizes NZ communities actually use) — would let NI weight the tank-material trade-off on NZ embodied-carbon and cost figures rather than Brazilian ones. (No new document to retrieve; flagged as a future NZ recalibration alongside the rainwater_harvesting cost data.)
Connections
Links to
Sources (1): CR_016
Technologies (1): Rainwater Harvesting (Roof Collection & Dual R…
Referenced by
EDT domains (1): D03: Water, Waste & Circular Systems
Technologies (1): Rainwater Harvesting (Roof Collection & Dual R…